This is only my personal experience of the last week but I have gone from an AVR350/PMC combo to an Onkyo 606/B&W M1 solution - purely for aesthetic reasons.
Yes the Arcam sounded better on stereo but I can honestly say that for AV I do not miss it. I feel quite guilty for saying it as I did love my AVR350 but whether its' better positioning of speakers or not the entry level onkyo just sounds really good fun for AV so I do wonder how the bigger Onkyos would sound.
I was quite surprised by how good the sound steering is and the basic settings from the Audyssey bit are quite good.
Having said all that I bet the AVR600 is a cracking amp but now I can have a dedicated stereo and AV system in the same room that do not compromise for probably the same price as the AVR600.
Happy days
