The MPC Live is a sampling workhorse. However there is one thing about the MPC architecture that doesn’t work well for live improvising (in my opinion), which is that you can’t have two sequences playing at once. If you improvise midi into a track, you can’t then advance the sequence while keeping the stuff you just created. The Octatrack (If I remember correctly) lets you copy that existing track into the next sequence before switching to it, so that’s a workaround the MPC doesn’t have.
The easy* solution is always two pieces of gear. One advances sequences for new melodies and song sections, and one is used just for adding in your improv stuff. I’ve worked this way a lot over the years.
Now that the Rytm has some great midi options, it pairs really well with the MPC, because you can sacrifice two midi tracks for triggering the MPC, while only sacrificing one Rytm sound slot. (use the tom pair for example). Then when recording into a track, do that in chromatic mode, where you can mirror the layout of your sample banks in the MPC - it’s a nice pad for pad representation, and you can easily scroll up through the octaves to get full use of an 8 bank sample program on the MPC.
Yeah, I’m just here to say that it’s a really fun combo!
*(gear-whore solution)