[spenner]

You can still playback and record via the MIDI controller with the mute button in the Instrument section engaged. It does, however, mute the VI Instrument recorded performance during playback.

It's basically the same as muting the MIDI region. However, it differs for me in this way... Say I have a session with a lot of MIDI tracks and regions. Sometimes I want to try another way of playing what I've already recorded. Instead of finding and muting the region(s), I mute the Instrument performance via the Instrument mute button and practice the new part during playback along with the other tracks.