It's not directly related to this thread, but i think it still fits the topic.
I just did a comparison between the MPC2KXL, MPC2500, ASR-10 (rack), and an E-mu E4X. The sample was a random track (jazz) from vinyl, sampled into the stereo ins, and played back from the stereo outs into a mackie mixer. I made sure to match the levels of all the different machines on the mixer... then i listened to them all forth and back.
The big shock for me was the 2KXL to be honest. I would have never thought this would sound so bad, but it does. There's no better word than "thin" to describe the sound. It lacks in stereo image, quality, bass... you name it.
In terms of getting a good clear quality without coloring the sound, the E-mu wins (clearly). The 2500 sounds surprisingly good tho, and in a complete mix i'm sure you couldn't tell which is which (the low pass filters on the e-mu are another story).
The asr-10 doesn't impress as much as the e-mu in terms of pure audio quality, but it still sounds very nice (compared to the 2KXL), but it has a certain coloration of sound that seems to mix very well with samples from vinyl. This is completely depending on individual taste however... personally i think it's a really nice sound for sample based hip hop beats.
I made this comparison simply because a friend of mine offered me his asr-10, and i wanted to see how it compares, and if there's even a need for another sampler in my setup. In the end i took it off his hands, and as a side effect, i've found out how bad the 2KXL sounds (and that i should also use the e-mu as a sampler, not just as a sound module). I will never use that MPC for sampling again, ever (but for sequencing, the pads and workflow are dope)!
Of course this is all just a personal opinion without any recorded wave files for other people to compare. So take it as just that please, my personal experience/opinion.
/end of personal rant
"It is no measure of health to be well adjusted to a profoundly sick society." - R. D. Laing