Dunno about the 2000 but the 740, which is the earlier version, has 4 DSPs, all of which can be used as insert effects at the same time, in spite of what the manual says. DSP4 is supposed to be just for vocal harmony but I got it to work on the main voice via sysex. The sysex overrides the manual settings on the keyboard and in turn the manual settings override the sysex. You can also apply the reverb, chorus and variation as well so between them you can make some real weird noises.

Bryan