Which AVR to purchase

Of course, you are forgoing all the newest DSP room correction technology (knowing that the deficiencies in your room acoustics are likely pulling the sonic integrity - and potential - down, likely) with these otherwise good sounding receivers.
That said, it's hard to beat the Arcam, as a tool, by-itself. It's got good refinement of detail, good balance of warmth and clarity, and quite sounding.
However, better power, body, weight, impact, transient response, etc, can be had with a modest newer tech receiver with 1.3a HD codecs and an outboard amp - not to mention the lastest in acoustics friendly processing.
But besides all that, considering reliability issues in past with NAD, I like the Arcam here. That and I can't see any receiver blowing the world away with sonic magic, so I don't even need to consider the Cambridge.

I've tried the NAD, Arcam, and now have a Cambridge. You can't go wrong with any of them. I'm very happy with the Cambridge.

See you can pick any of them and expect about the same "realm" of performance. My experience says Arcam has a better track record of maintainability than the NAD, if that helps. Cambridge, can't tell ya.
Wait, doesn't cambridge make entry level speakers and such?

ARCAM is what I would consider, however, I am holding off on the AVR350 and leaning toward the DENON AVR4308CI for the time being due to "Next Gen" line-up....

I agree with Iplaynaked (he plays Canasta). I just replaced my Sony CRT and DVD, Integra 6.1 receiver with a Blue Ray, HDMI, True HD, self calibrating reciever, and compatible components. The improvements in both audio, video, and switching are simply stunning.

I gave up on getting this HT to image like my two channel and resigned to enjoying video/music and music/video's. Spend your money on decent and sensitive speakers and an up to date receiver and player.