JACKHAMMER
I think a diff. of ~10w on the sub is not a whole lot.
There are a lot of things that measures a good sound system because wattage isn't everything. The system response, the imput impedance, and the crossover frequencies also have a lot of weight. Not to mention how well the subs and the satellites are built. I mean you could have a 1000 watt amp and if your satellites and subwoofer can't handle it, then you have a pretty crappy system. I own both the ACS48s and the 4100s and the 4100s blow the ACS48s away. Not that i use either since I also have the Klipsch Promedias. =o)