Early results with my old speakers are very good for the AVR600. It excels at both music and movies, though there is much more tweaking I need to do, especially with integrating my sub.
After manual set up, ran the auto EQ for giggles, it was way off in distances and made the sub either boomy or non existent, depending on what was playing. ARC for the Anthem was dead on.
Arcam has been tight lipped on what exactly the 'Room EQ' does, and I would not be surprised to find out not much at all. It is by far the worst of the three, but I will run it a few more times just to see. While I do not depend on Room EQ, I do try it and in the case of ARC found it to be amazing for both music and movies, Audyssey was great for movies but not music, and this Arcam EQ doesn't seem to be much good for anything.
I am also experiencing one of the issues others have reported, which is the popping sound when switching sources(more like a 'thud' from the sub woofer). So far no handshake issues, but I never did watch a bluray, just TV and music.
There is a new 2.3 firmware coming out in a week or so, hopefully that will smooth out the popping. With lock in to the signal can be annoying. like when skipping over commercials with the DVR, when the show starts there is a long delay in audio as it syncs on the signal/reads the audio flags. Annoying, but I have had other units in the past with that issue.
It is worrisome(the issues with the unit), hope it doesn't become a deal breaker as so far this Arcam really sounds like a winner.