NAD M25 vs. Butler Audio 5150

Starting to get the itch to upgrade my NAD T785 AVR with separate components. I'm a huge NAD fan and have done some research on the M25, but I also stumbled across some positive reviews on the Butler 5150. I'd value anyone's opinion, (a) if an upgrade to one of those from the T785 would be noticable, and (b) if they've ever compared the M25 and 5150. All 5 speakers in surround system are Paradigm, with the mains being the Paradigm S6 v3. Also have 2 Velodyne DD-12 subs. I love the T785, and get many, many compliments from my friends, but I like to play my music loud, and I am starting to sense I could use a little more horsepower at the upper end.