Glenn, welcome. I wouldn't believe nonsense about the "sound" of a receiver, such as appeared in the Widescreen Review, for even a nanosecond. If an amplifier, such as the one in your 3808, amplifies the full 20Hz-20KHz range with flat response and inaudibly low noise and distortion(as it does)that's all that any amplifier can do: make the sound louder without adding any audible sonic coloration. If an amplifier was found that did in fact sound different, there'd have to be something wrong with it. The editor of The Audio Critic summarises this very basic point of audio technology very briefly in
"Electronic Signal Paths Do Not Have a Personality!" .
Your 3808 is certainly equal sonically to the Arcam and superior to it in features, and at a lower price. No "upgrade" of it is necessary.
You might consider a more powerful sub if you want more bass output or extension. In that size room and supported by a good sub, the M22s should be excellent and I'd have no idea otherwise of how to achieve "more performance with 2-channel music". Relax.
