cb, what front, center and sub are you using? How far away are you?
When you say the Onk was meh and just different, was that for movies, music or both? If for music, 2.1 or surround?
I have a small HT room and overkilled it with 7.1 many years ago when I started with my Axioms - go big and stay home was my philosophy even though it is a small room ;-) As per my signature, I use M5 on walls for LCR with 4xQS8 and an EP500 (the older gen ported version). I'm a believer in vertical center channels if your space allows for it.
Biggest use is movies and gaming. But when I listen to 2 channel music it's usually surround - this is where I think I enjoyed my Pioneer more than the Onk in the ability to play with the center focus more easily.
Room is ~12'x14'x7' (WxLxH) but oddly shaped and not symmetrical. Seating is ~8 feet from front wall.
The Onkyo is equally as powerful as my old SC-05 Pioneer, but is a bit 'softer' in sound if I have to describe it.
If my current Denon would pass the video stream, unmolested, I would not swap it out. It may seem trivial, but I like to see the menu screen of the audio processor on my display.
Which Anthem AVR would you suggest? I have no experience with Anthem.
FWIW, The AV sales rep I am working with suggested the Denon X4500.
I also like having the menu on the TV, one of the details I like on the newer receivers.
No experience with Denon, but for Anthem I'd just pick the MRX series with integrated amps that works for your setup, or go to the AVM 60 processor only and add the amplification of your choice.
Please keep in mind I am basing this on conversations with several people and my own research, but I've not done any critical listening of the Anthem products so I cannot offer my first hand experience.