This was Alesis's first foray into the world of synthesizers, as far as I'm aware. My particular unit has defects (the front panel buttons and knobs are very unstable), the seller decided to not even put it in a box. It's got 64 voice polyphony, and so far from using it I haven't been able to hit it. I'm not sure if this synth is only 64 voice (with up to 4 voices making up for a patch) or 64 note polyphony (if it's the latter, that is bloody impressive). The sounds are all cheesy and very much still usable today. I've been sneaking this in my productions, I'll leave it up to the listener to find out.
The only areas I think this lacks in are the filters, they're non-resonant and lack any real character. Also the effects, it's derived from one of their FX units (Quadraverb, I think). It's good enough, in fact I think it adds a lot to the base sounds as a whole, it's got a tasty reverb, a nice delay, and a chorus, but I would've really liked to see more. This was released in 1993, and compared to offerings from Korg, Roland, and Yamaha it is kinda lacking.
Overall, I'd heavily recommend it if you're looking for a new spice of sounds that's neither Roland, Korg, or whatever other popular manufacturers you think of. If you can, get the QSR. It's an updated version of this and adds a ton of much-needed features and is generally part of the more popular QS lineup of products from Alesis (based on the same concept though)