As for my A820, like you, I'm loving it. Thanks to the Aventage threads here at AVS, we get lots of tips to better take advantage of it. The one button (Scene) control is a major convenience and I especially am a fan of the tablet AV Controller. I'm seldom without my tablet and the app allows me to manage the AVR from anywhere in my house and even from my outside shop. Getting music without walking into the LR is fantastic! And that trick to get the Main receiver audio out to Zone2 works fine (turn on Main and Zone 2, then mute Main). The A820 (and other Aventage models) are just amazingly versatile. And the audio performance is brilliant. Some complain about Yamaha's DPS modes, but I think they miss the point of being able to modify them. With my large viewing room, I'm able to expand the audio image to provide a full theater-like experience in Spectacle -- but with better audio, of course.
Frankly, I'm still playing at times with the customizations possible. I've had to go back to normal life activities, but once in a while when watching a movie on my own, I get to thinking "I can make this sound even better." (My wife hates it when I do that with her watching, so solitude has it's advantages. ) One of the major attractions of the A820 is that there is still so much to explore.
On a side note, we're going to make our once yearly trip to an actual theater to see "The Lone Ranger" tomorrow. Got to see Johnny Depp as Tonto. (I have always called my dog "Tonto" even though my wife named him Dante.) And tonight I'll give the A820 a thrill with my annual viewing of "Independence Day". Good to have a feel-good movie for the 4th.