Thanks for your input Mr Peabody and turbo8888. My AV installer is swapping out my RCA's for balanced cables at a minimal charge so I might as well go for it. Speaking of which (and I know I should probably post this question in a specific forum), anyone believe in upgrading power cables? Make any tangible difference to sound?

I see the AV8003 firmware can be updated directly via the Internet via the network interface. I'm not sure if this update just affects the networking portion of the AV or if full-on firmware updates can be uploaded in this fashion (e.g. to support new functionality such as Auddysey EQ over bitstream). Anyone have any more info on this and/or previous experience with regard to how actively Marantz keeps their firmware up-to-date?

My AV/MM combo should be arriving this evening – holding thumbs.