As a former AVM2 owner/ Now a Meridian 565 owner I can tell you my older but upgraded to 7.1, Meridian KILLS the AVM2. Dynamics and clarity are the biggest areas,where it does this.
It depends on your priorities.--Meridian, No 6 ch input, no video switching,no 2 zone stuff. BUT--- if 2ch/5.1 "sound" are highest on your list---don't listen to a Meridian basher. Talk to someone whom has had one set up right; in there home.
OK, no AVM20 input,sorry. Here's how it goes. Anthem is priced much lower than say Mer.568. Practically all the quality / cost is in the sound. Anthem gives you all the bells/options. So, with what you pay for Anthem,you get a lot. Don't think for a minute the sound quality is equal to Meridian.AND, like all processors,the amps and speakers they are used with; matter.