I am sure that others have responded to you earlier but here is the truth. The new samplers Blow away the older series with one huge exception. Midi triggering is a large problem for the new Akai S5000/6000s. fast and complex midi data will cause the akai to lock up, play late, or trigger long after the sequence data is over. Pretty crummy huh? I posted more detailed info where you posted your question. If you own one already, then I seriously suggest you read my post, and test you piece before you totally commit.
-Eric