Dan, the "used" 3808 might be a very good deal if it's a factory refurbished unit or is being offered by a reliable source. One point to check on the 3808 is to see if it either came with or was upgraded with the package of improvements that came out about three years ago, which included most notably Audyssey Dynamic EQ, which older 3808s didn't have.
As you say, you'll get better bass management and other features, particularly Audyssey MultEQ XT, which should justify the switch. As far as the "increased power" though, that will almost certainly be insignificant. The difference between 105 and 130 watts is only about 0.9dB in maximum speaker sound level. For example, in typical home rooms the M80 could deliver about 105dB with 105 watts for a brief peak at the listening position, which would increase insignificantly to 105.9dB with 130 watts. So, the power rating is really of little concern for modern HT receivers rated anywhere in the 100-150 watt area.
At least four of our members have used the 3808 with great satisfaction, and you'll likely be very pleased as well. Incidentally, enjoyed your "Why blue?" story, but it's even better if Stalin comments that he knew it would be the only question that Putin had.
