If you can get one for around $100 or less they are a cool adjunct to an existing midi system. But if it is to be your only midi synth, then it won't do the job being only really 4 note polyphonic and no drum section. However if you are buying it just to expand your range of sounds then it is quite cool to program from the front panel.
Certain types of sounds it can do quite well, (eg. synth brass, bass) Sounds that take advantage of the multiple stage envelopes can also be very cool, and using tone mix to layer sounds is effective for mono lines. The general tone of the CZ tends to be quite digital with an odd upper mids boxiness that is particular evident with percussive sounds. But that is not necessarily a bad thing, as it helps add to it's quirky-but-unique sound which can work well in helping to stand out in a mix.
Sum up .. a good unit for experimentation but not as the main sound making device in your studio.