Using this machine is pretty simple overall. While there are a bunch of sounds, there isn't an astronomical number of them, meaning you can get around them pretty easily and program your favorite ones for easy access. THe hardest thing about using this keyboard is the size of the keys. These keys would be relatively small for any player who isn't a child, and my hands happen to be quite large, so I sometimes struggle to fit the notes in. However, I think this is a relatively small problem considering that my main use of this synth is for single note lines, though. The manual is really good at explaining how to work the synth, and it definitely made things easier once I got started.
I love the sounds that come out of this synth. Don't let the size fool you; this guy really brings it! My favorite sounds are ones that can best be described as throwbacks to 80s new wave and 90s dance music. I think that if this is what you are looking for, these sounds are great. It also does a decent job of emulating mellotron and organ sounds, which I wasn't expecting. I wouldn't buy it specifically for those things, but they are a nice bonus. To top it all off, the Vocoder is undoubtedly one of the best features of this synth, and almost worth it for this alone.
The sounds are only as realistic as a synth can be. It emulates synth sounds, not the sounds of real instruments, so I'd say they are overall pretty realistic. There isn't much in the way of touch sensitivity, but the sounds that come out of this guy aren't really the kind you'd need a whole lot of sensitivity on anyway. I like some of the effects, particularly the modulation and reverb effects. I haven't had a single complaint with any of the sounds that have come out of this synth.
This synth came highly recommended by a few friends of mine. They didn't steer me wrong. I am very happy with this purchase. I like the diversity of synth sounds, the vocoder, and the relatively compact size of this keyboard. It's a bit pricey but I am very much convinced that it's worth it. I think that the sound quality is solid throughout, and assuming you use the right amp or DI this thing can work wonders. If broken, I would certainly replace it.