As the owner of both a PSR2000 and an Enqoniq SD1 Synth Workstation I can tell you there is absolutely no comparison between the voice editing capabilities of the 2k and the SD1.

Yes, you can do quite a few things with the 2k (LFO's, effects, Attack, decay, harmonic content etc) (and I have to say this is all I've ever wanted to do on the 2k) but on the SD1 (which is now 10 years old and so I expect things have moved on) you can select up to 6 different waveforms as "oscillators" then, for each of these voices, there are three complex envelope generators and LFO's assignable to most variable parameters. this is the simplified description!

Most synth "I create my own sounds" owners will find the voice "twiddling" capabilities of most arrangers (and include my 2k in this) extremely limited.