L.R. Baggs M-1

Pickup features: Passive humbucker with single coil sound...
Impedence or other specs:

Model of guitar or bass: Taylor
Position: neck
Pickup being replaced: ES
Other pickups on guitar:
Artists using this pickup:
You musical style(s): Many
Reason for pickup change: I Questioned whether I was paying all this money for the the insesent humming and hissing, or the overpriced sound and excesive cracking. Then I realized, I don't Like this system...

Perceived output level: This pickup has the same output level as a Sunrise Pickup...
Tone:
Sonic evaluation: Tayler/M1 Through a Para DI and AER acousticube amp.

For which styles and positions is this pickup (un)suitable: Many

Comments: I have liked LR Baggs for a long time, so i searched there products when i was not satisfied with the Taylor ES. Even though i don't care for the ES, it is not that bad. I just don't like it that much and that is my opinion. However, there is a drastic difference in quality and sound with the ES and the M1/Para DI. It took care of everything that i disliked about the ES and added a lot more. It is a very naturual sounding pickup (surprisingly so for a Magnetic). Also, i think that it gives a guitar a great look.

Pickup features: Passive humbucker
Impedence or other specs: Senses top vibrations and blends with humbucker signal

Model of guitar or bass: Larrivee SD 50
Position: middle
Pickup being replaced: B Band AST
Other pickups on guitar: K & K Trinity (passive)
Artists using this pickup: No idea.
You musical style(s): Contemporary Fingerstyle
Reason for pickup change: Huge feedback issues at low volumes. Needed a quiet passive pickup.

Perceived output level: It's passive: the output is medium-low
Tone: Very "glassy" (a la single coil strat), strident mids and focused bass: very bright and clean
Sonic evaluation: As a stand-alone pickup the M1 was not doing the job: making a mahogany guitar sound more electric than acoustic. Warmth was lacking. However, the enlarged soundhole was too big for a Feedback Buster, and I play live music. Baggs says that other passive or active pickups can be wired to the ring, so I installed a K & K passive bridge plate transducer. I am mixing the two sources using a Raven Labs PMB-1, and have gotten back the warmth and sparkle I desire. In other words: it sounds like a mahogany guitar again. To keep the feedback under control, I roll off the bass on the K&K--using it for mids and highs. The focused bass from the M1 really shines in combination with the other pickup.
Another discovery I made was that you can place a strip of cloth or cork where the pickup attaches to the soundhole. Not only does this save the finish on your instrument, but it also tones down the "glassy" personality of this pickup. At Baggs suggestion I also use their DI Box--and it helps somewhat to scoop out and focus the strong mids at a warmer frequency.
Other tricks: you don't need the magnetic pole pieces set very high to get a good signal. In fact, they are so strong that they can cause the same kind of sustain-killing string pull that you can get on an electric guitar. Not good for acoustic playing! I have mine set 1/16" above the face of the pickup.

For which styles and positions is this pickup (un)suitable: Fingerstyle/Worship Leader

Comments: Here's the bottom line: It took a lot of messing around to get this pickup dialed in. Given my trouble with feedback, it was one of the only viable choices. But, I don't think this pickup constitutes a stand-alone set-up for someone playing higher end guitars--those who care about pure acoustic tone. Together with the K&K, the tone is pretty desirable, but I think Baggs makes other pickups that are much easier to use right out of the box. (IMix and double barrel)

Pickup features: Triaxial Humbucking
Impedence or other specs: Magnetic Pickup; no battery requied

Model of guitar or bass: Sigma
Position: neck
Pickup being replaced: N/A
Other pickups on guitar: N/A
Artists using this pickup:
You musical style(s): Praise & Worship, Blues
Reason for pickup change: Needed a way to amplify my acoustic guitar

Perceived output level: About average for a mag p/u. Requires a preamp before hitting the main amp.
Tone: Adjustable pole pieces let you emphasize/deemphasize each string's contribution.
Sonic evaluation: I run my M-1 into a Yamaha AG Stomp for my preamp. From there, one output channel goes to a Roland KC-100 amp for monitor and the other channel feeds the house PA. I've also plugged it directly into a Fender Twin, and it simply sounds awesome! It's a little weird hearing those acoustic tones coming out of a Twin! Warning: Even though this mag p/u is very resistant to feedback under normal circumstances, when you've got 100 watts of tube power on tap and close by, you can push enough air to set the strings into auto-vibe and it can produce some honking feedback (or sustain, if you know how to control it). When I play in a church setting, I don't turn up my monitor loud enough for it to begin to be a problem. The AG Stomp lets me notch out up to 5 problematic frequencies with a quick stab to the FB Reducer, but I have rarely used it.
The pickup, as others have noted, does a fantastic job of translating your acoustic sound into a signal that can be amplified. For me, the appeal of a passive transducer was very strong. I have watched my bandmate delay practice to go or send someone after 9-volt batteries (not cheap, btw) too many times. On the other hand, no player in their right mind would want to sacrifice an authenic acoustic tone for the convenience of no battery.
To be honest, the M-1 is not going to sound as good as a properly positioned, high quality condenser mic. But it get's pretty doggone close. The suspended coil (lower one) transfers the vibration from the guitar top into a signal that combines with the top coil to bring out the acoustic quality that you hear unamplified. I assume the triaxial term refers to the second coil's configuration allowing it to transduce vibrations in three mutually perpendicular axes. I couldn't say if that's hype, or not. But I can testify that the sound is mighty pleasing to my ears and is a faithful representation of the pure acoustic sound.
As for how it interacts with my preamp, I like set the AG Stomp to 100% direct when I use my guitar with the M-1. That's how much I like it's tone! When I play through it with a piezo equipped guitar, I generally use a preset with one of the microphone models, instead of the direct tone. I also tweak the blend knob to get a mix. The cool thing about using a parametric preamp is that you can boost or cut the lows, mids, and highs to further shape your tone according to your mood and the environment. You really need an offboard preamp to take advantage of this pickup.

For which styles and positions is this pickup (un)suitable: Praise and Worship music. The M-1 is a super value for the price.

Comments: If this pickup became damaged or stolen, I'd probably be looking for another guitar, too. Might get a Taylor Big Baby or similar. Yeah, I'd get another M-1. As long as the soundhole is at least 3.5" or more in diameter, this thing will fit. And it is easy to transfer to your other guitars. However, if you use the included Mogami cable to hang out the soundhole instead of installing the included endpin jack, you'll need to ensure you clip the cable out of the way of your strumming. If you don't, you'll find out that there's an unpleasant transmission of vibration right into the heart of the pickup, and it won't be pretty.
Aesthetically, it isn't as unobtrusive as an undersaddle p/u or I-beam type. But the cream color does go well with both dark and light colored guitar tops. You need to change your strings in order to install the thing, since it has to be tilted to get the clamp "ears" in position, and you need the strings out of the way to do that. But it only requires a philips screwdriver and takes less than 5 minutes to install. Then it depends on how fast you can re-string and get it plugged in.

Pickup features: passive humbucking, body sensitive
Impedence or other specs:

Model of guitar or bass: CA Guitars Legacy acoustic
Position: neck
Pickup being replaced: none--acoustic
Other pickups on guitar: none
Artists using this pickup:
You musical style(s): singer songwriter, rock, worship, folk rock
Reason for pickup change: I bought this pickup after checking out its smart design and reading its great reviews. I wanted something that would _sound like my guitar_!!

Perceived output level: You should run it through a preamp--something high-impedence.
Tone: Even, balanced tone. Natural sounding--representitive of the actual guitar. You can adjust the pole-pieces.
Sonic evaluation: I ran this into a house system that had a preamp and mixer, coming out through a PA.
Like I said already, very natural. Works well for strumming and picking. Doesn't muddy up, sound harsh, or sound sterile--doesn't sound like a humbucker. Much nicer, but zero hum.
I got several comments about how beautiful and natural the guitar sound was while using this. The sound man loved it too!

For which styles and positions is this pickup (un)suitable: The setting I used it in was alongside a piano and a few vocalists. If running through a PA or through a preamp and mixer, I think it'd work fine with a larger/louder group.

Comments: Well, I pretty much covered everything. I think it's a fantastic pickup, representitive of the guitar and very natural sounding. The great design takes the sound from the strings and body, and keeps everything hum-free but vibrant.

Pickup features: Humbucking multilyer pickup
Impedence or other specs:

Model of guitar or bass: Wechter 5100
Position: neck
Pickup being replaced: No
Other pickups on guitar: Piezo + condenser mic
Artists using this pickup:
You musical style(s): Various
Reason for pickup change: I needed sound of normal magnetic pick up, so I tried many others that just added garbage to the sound and could not mix with piezo nicely. M 1 was just my last experiment.

Perceived output level: It is medium hot.
Tone: Very balanced. It is not usual magnetic pickup, very deep with some tricks in construction, it brings completely different sound, more like very good microphone. It means I did not found what I was looking for, but I found way better solution for my guitar and now electrified guitar sound is way better in total.
Sonic evaluation: I use various amps and very often paly via PA. This combination is killer.

For which styles and positions is this pickup (un)suitable: Rock, pop.

Comments: I will put it to my other acoustic guitars. I believe it is MUCH better than many other solutions on market.

Pickup features: passive humbucking (sensitive to movement of guitar top)
Impedence or other specs: low impedance?

Model of guitar or bass: Martin 000-28ec
Position: neck
Pickup being replaced: none
Other pickups on guitar:
Artists using this pickup: not sure
You musical style(s): singer songwriter/ fingerpicking/ blues/folk/ latin/ jazz/ rock etc.
Reason for pickup change: the guitar came without a pick up and I wanted something that would capture the voice of the guitar.

Perceived output level: low
Tone: This pick-up has a very even tone and represents the sound coming from your guitar to some degree. It also has adjustable pole pieces. So if you don't like the sound you're getting...switch it up.
Sonic evaluation: using a martin 000-28ec and practice through a small practice amp.

For which styles and positions is this pickup (un)suitable: blues/ folk/ singer songwriter. this pickup is not a 'lead' playing sort of item. it's full and precise, but not ready to cut through a 10 piece drum set and a couple of full stacks. This is more for an acoustic ensemble or a solo act. Very good pickup for this purpose.

Comments: This is a great pickup. Certainly not the 'holy grail' but comparable to the Sunrise and the Rare Earth. Try one out...you won't be dissappointed for the money. You can tap on the top of the instrument and get a percussive arsenal from the guitar. I would warn anyone with a 100 dollar beater. This pickup WILL represent your guitar. If you find that it sounds bad, check your set-up and know that if your guitar is strong on the treble or it 'zings' a bit too much, chances are the pickup is going to represent that. I have a small body Martin and it's not wonder that the pickup is midrangy. This the best bang for the buck if you're not looking to rock out. I've owned a Dean Markley pro-mag, a Fishman Neo-d, and a Fishman Rare earth. This one blows them all out of the water. I've also used a regular piezo pickup and an i-beam and the M-1 is simply in another league.