I've been sequencing on an RM1x (predecessor to RS7000) for four years. I just bought an MPC 1000 two weeks ago. While there are many differences, I'll sum it up for you: The MPC is all about live recording. I can record an entire song without ever having to stop playback. But when it comes to post editing, I'd rather re-record a track then have to edit it on the MPC. The RM1x is all about post-editing. There are over thirty different "jobs" that I can perform to a track after it's recorded. But I could never record more than one track without having to stop, select a new instrument, change sections, etc... There is no "flow" like there is with the MPC. That's the major difference. Of course, the RM1x also has built-in sounds and the RS7000 has a synth engine and phrase sampler. Honestly, I haven't touched the RM1x since I started sequencing with the MPC. I use an E-mu ESI-4000 with sample cd's and a few VA synths for my sounds. I've been very happy with my MPC 1000. For hip-hop, the MPC cannot be beat. For more complex compositions, the post-editing power of the RM1x is unmatched. That's my two cents.
Peace Out \/