I have the much older AVR350 (the model with no HDMI audio input, only video throughput) and while it seemingly sounds good in direct mode and has a decent amount of power, it also had some peculiar issues.
The bug I encountered was that I moved the amp from the upstairs hi-fi to the downstairs TV and suddenly there was what sounded like a ground loop hum. I checked all the cables, changed extension leads, unplugged everything and replugged one by one but it wouldn't go away. After a few weeks with it annoying me regularly and many fruitless attempts to fix it, I finally went through every option in the slightly torturous menu system and tried turning all the speaker outputs on and off alternately. If I remember correctly I had to toggle the subwoofer on and off (I had no sub connected and had it disabled in the menu system) and suddenly the hum disappeared. Toggling it on and off in a certain order would reinstate or remove the hum. Helpful.