phukin hell they feel different!!!!!
I found the 3000 to be very stiff in the pads, you had to hit them hard to get them to go full level. I don't hit the pads as hard as others I've seen with bigger fingers (Like Pete "just look at them shytz yo!" Rock). Some cats get on my 60 and I'm like easy killer, I gotta fix anything you break! but the pads can take it, it is just a different style.
The 60's pads are easier to trigger full level and close to full level. I find I have to deliberately want a lower hit to get one. No accidental soft hits unless some complex stuff has me square dancin'.
The 2000 has cool pads, a little less solid than the 60 and 3000, but I had no problems with the velo response. I hate the pads on the right though, but it has it's perks.
The 4000 has nice pads, they are solid, it doesn't shake the machine to hit them, the travel on them is less than on the 60 which would take some getting used to, perhaps to minimize double triggers, but I am not sure about that.
That said, I'd choose what I have, the MPC 60 with all upgrades. In second place is the 3000, just because of the great layout, button per function and decent sized screen.
After that, it would be the 1000 once the bugs are sorted out, then the 4000, and the 2000 / XL in last place, did I mention I hate the pads on the right?
