Kurzweil K2000RS

Software version 3.18 Janus
Don't judge this synth with Y2K ears by presets made in the early 90's
Patch editing is easy at the basic level but can become as difficult as you care to get. I have yet to find a really good patch editor for this guy.
The manual is very good and quite thick. Despite being two volumes of dense reading, the manual still only scrathes the surface. That's a compliment to the Kurz design team.

Polyphony seems limited at first. (only 24 voices) However, in practice, those 24 voices go a lot further and fill up a great deal of sonic space compared to 64 and 128 voice synths that require massive layering (bringing polyphony way down in the process) to sound this thick and juicy. I really don't think there is a more flexible synth out there.
On-board sequencer is good but no-one with a computer is going to be impressed.

If you have never used anything other than the factory sounds, do yourself a favor and do a google search for brian cowell. Download everything you find by him. His sounds and tutorials should be required listening/reading for any serious K2xxx user.
This instrument is the one common denominator in every pro studio I have ever worked in. That says it all really. To nit-pick:
The output levels could be a little hotter. I believe that a lot of less-educated players judge the Kurzweil as inferior during side by side comparisons in music stores because this synth tends to be about 6-10 dB down from your typical mass-market synth. It's common to hear louder as better. Kurzweil has "fixed" this in the K2600 series.

Push it hard enough and it will crash. However, in normal use, it has been rock solid. This thing lives in a built-in, floor to ceiling synth/sampler rack in one wall of my studio. I'm not moving it unless we move the entire studio. I tend to use lower-quality (cheap) gear for live work. Cigarette smoke and drunks with pitchers of beer in hand is an accident waiting to happen for gear I'm this fond of.

I like this company. They have, in the past, been very helpful and seem to promote a creative spirit to some extent. It's so rare these days to find any company that gives a damn about creativity. I have not had any contact with them recently.

I would replace it with a K2600. I have way too much gear. I include among my instruments most of the current, hot products and a large number of vintage instruments. I tend to go the Kurz fairly quickly when a client needs strings, analog punch or a nice bass patch for a track. I wish the fan were quieter. That's probably my only real criticism and is the reason that I will soon replace this with the K2600xs. Given the current price of these on the used market, I would have to say that the K2000 is the best value going.

Running version 3.87 me thinks. Presets are pretty ridiculus (i like #123 = Glockenspiel), but good for learning, delete the layers you don't like, tweak and save your new stuff. It is "pretty" easy to "use", but if you want to USE it, you will have to do some tweaking and that isnt that fast, it's quite tiresome actually, I have just playing with it, trying to make some bubbly drums for a song, but now I'm sitting here typing this. It really is slow, but I could imagine when you get some more experience with various fun stuff, it would be easier, but it would still be slow pressing the buttons in the right order: and then back and then in again, back out, new parameter adjustments, back to LFO etc. It's not instant gratification. Saw my friend operating his Akai s-2000 and I couldn't keep up, it was just in his fingers (like he could see anything on that tinny display anyway).
The manual is good. Good toilet-reading text. My first focus was the "shortcuts" and various other "hidden" combinations of button pressing, once you get that then punch and pull all you can. I made some loops that weren't that repetetive in the sequencer, and then i pushed and pulled. Some knobs are almost a must for this machine, a pitch- and modwheel isn't enough, for me.
Oh I have to rate "ease of use"? Can't do that really. It's as perfect as can be with that "small" display. Looks a little DOSsy? Killer refresh-rate though. I think akai's displays are nicer.

Poly=24 Doesnt seem like that much. First I thought that a "program" with 3 layers would use one voice and I thought that's enough, but every layer in the Prog eats one voice. Maybe not enough. Haven't run into "big" walls yet though; I'm a pretty minimal guy.
The great big V.A.S.T thingy? Variable Architecture Synthesis sums it up pretty good. Lots of variables. Isn't "that" impressive anymore, I wasn't really impressed, more in the likes of: "that's it?" You have some small block which can be fed all kinds variables and you try and feed them some good numbers. Wouldn't have minded some more blocks though.
The onboard EFX are ok for a little reverb but not much else. Can only use the efx on 1 output, so it's pretty useless.
I don't have a sampling-option(smp-k), but I find out that that was ok. Can still load .wav's and play with them like a normal sampler, but with all the VAST'ing you can do to it, nobody needs to know what samples you loaded.
30-pin simm ram can be added. I've only found old 4 mb modules on the junkyard. Can't find any 16 megabytes, so stuck with 16 megabyte for the moment, which definetely isnt enough for me.
A HD can be added (max 2 GB. Check sweetwater.com for listed compatables + misc. storage.) No need for the HDC kit from kurzweil, can do it yourself.
etc. etc. etc.

I see a lot of people are using their Kurz'ers for orchestra stuff, so I guess that's good if you got one of the newer K's. 64 MB Max wouldn't suffice for big sampled libraries.
This machine wasn't really meant for any particular musical style, it just gave you the freedom to mess around.
Yes yes yes. The sound is ok, seems like you got a lot of space for all kinds of frequencies, also seems like the bass-stuff isnt really that bassy. Maybe it's just me. Somebody is probably thinking about killing me for saying that I prefer the sound of an Akai. Don't know why, but I like Akai's sound. Sometimes I feel like the sound is too far away from me when listening with headphones. But the sound is good anyways, I have just yet to hear a good jungle-style bass-drop.

You can depend on it, I've been inside it and i couldn't really imagine anything moving around in there. Some say the diskdrive is crap, but it seems to work fine.
I would take a backup of my disks with programs and the hope that my samples will load of my old Jazz drive.

haven't dealt with them. I read some good and bad things about sweetwater who are kurzweil fascists (so i've read. Kurzweil is THE only ehm synth ever manufactured. Akai = die!)

If it were lost, then I wouldn't have it, and that would make me a little sad, but not that much, since I shouldn't really have spent my money on anything with all those juicy native-instruments plugins.
I've been composing enterily on my pc, when I got some money I looked around at what was out there, and this is the only thing that I could imagine that I could have some fun with it. Don't regret buying it, but I should've (just) upgraded my old farty PC.
Overrated but good (as in NOT "fucking amazing") product.

the presets are good but it should not the reason to get this machine
programming is the key word for this machine....progamming the sounds
is like openning gifts on x-mas morning.the only gripe i have is their manuals they really dont hint about the full power this machine is capable of.

kurtzweil as a company was pretty helpfull i had a little question
about sample ram vs the p-ram they answered perfectly.
i had the k2000r and evetually got the sample option which
is very fresh.

if this was stolen id probably have to replace immediatly

Software version 3.18J::

Look on the internet for some tutorials or read the manual, as this
_synth_ is not for types who are satisfied with living in preset land.
This module approaches the "all you need" level, but it is highly
recommended to use it alongside an analog or analog modeling synth to
get the full potential out of this monster

Almost EVERY single paramater on this synth is programmable via midi.
What this means is that you can have a little midi knob box and have
knobs controlling filter cutoff, resonance, env depth, lfo speed /
depth, distortion amount, etc. etc... all programing is done via
the backlit LCD which is a very nice size.

OK, this thing is very PHAT. The synth architecture was VERY well
thought out and was created with the musician in mind. The onboard
sounds are typical, but if you are going to be using preset/onboard
sounds than this synth is not what you are looking for. This thing
can make ANYTHING, as its architecture is virtually unlimited.

Solid, made out of steel. I gave it a nickname, "industrial strength"

Never crashes. Sounds perfect.

Never dealt w/ them, but my friend needed rack ears for his and
they sent them to him the same day free of charge!

This thing is one of the most versatile and powerful sampler/synths
available. If stolen I would buy a gun. If you are SERIOUS about
your electronic music and you LIKE learning synthesis / programming
than look no further. The sampling option makes it 1000% more
versatile. I make goa trance, this module is SICK!!!