NAD T785 vs. NAD M15/M25

Itching for upgrade and curious if anyone has an thoughts on the difference in performance between the 2 units above. Currently running a 5.2 Paradigm S6v3 (mains) system with T785, and sounds pretty nice, but looking for a bit more bang, and wondering if the additional cash outlay for the M15/M25 could be justified. Listen to stereo music 70% of the time and home theatre 30% of time.