I took the other approach: since I already have an audio interface (Native Instruments Komplete Audio 6 MK2) for my MPC One in sedentary configuration, the MPC is just one of the instruments going into the MX-1: one mono channel (often a Mini-D bass) through TRS jack, a couple of TRS jacks to a stereo channel, another stereo channel through SPDIF (that one limits the whole MX-1 to 44.1 kHz). Also, a TRS jack sends a mono channel to the VT4 (microphone on the audio interface, for MPC-driven MIDI vocoding) that outputs both USB to the MX-1 and a mono channel back to the MPC for resampling - at this point I'm just fooling around, but it is mighty fun.
The MPC was my everything studio in a box, but I felt its studio leanings as a limitation: jamming live (or, let's be honest: noodling) or explaining to my young kids (actually the first reason why I wanted a TR-8) doesn't vibe well with pages and menus - hence acquiring cheap one-knob-per function devices for a "live fun" setup: TR-8, TB-3 and MX-1 (System-1 coming because I'm a complete sucker for Roland's Aira strategy, though at today's flea market prices) - with the MPC clock master (the rumor is true: the MPC doesn't like not running the show)... But I also still use the MPC alone with just a small external keyboard - running the whole pipe dream is unashamedly fun, but in terms of actual musical making I'm not sure it increases productivity at all: the MPC's integration is seriously powerful.
The MX-1's "PC" USB port goes to an actual PC (Debian) that runs Vital (gratuitous extra synth, MPC MIDI driven), Audacity (to record the master out) and Open Broadcast Studio (because I enjoy fooling myself that me making things go honk might actually entertain anyone someday).
And by the way, for such an incompetent as me, the MX-1's mastering chains are very nice: pretty sure that the MPC could pile master effects similarly (with 3-band compressor à la YA Mastering Template), but choosing a chain and obtaining enhanced sound in such a brain-dead way is nice - I like n°2.
