I've never seen/heard a mz 2000, but ...from others' decriptions, the mz2000 was the better keyboard. It is more versitile...being able to use more than 1 DSP effect at a time, and generally more parameter controls. The wk3000/3500s are also good keyboards, with great tones, ability to download new tones/rhythms/effects. Also they have a 76 note keyboard. The down side on the 2000 is that it is out of production...so you would have to find a used one.