It all depends on how you want to work. Personally I think the MP-7 and an EMU or yamaha rack sampler would be a more versatile package than the MPC.
But then sample loops aren't a big part of what I do. I tend to make most of my music from scratch, and I prefer to buy gear that already has a bunch of preset sounds. I don't care much for making my own instruments. I'll tweak a preset, but on the MPCs you have listed, I think there is a lot of setup involved in building say a rhodes, or a wurly, or a moog, where on the MP-7, they are already there.