I agree with Drrdiamond on this. It was not my goal to simply have more power, and besides, the wattage output gain between the 400cx and 300cx is really insignificant when it comes to sound pressure levels. My goal was to see if there was truly a qualitative difference at the same SPLs I normally listen to (usually b/w 70 to 80 dB with digital meter at 10 ft). The 400cx made a qualitative difference. I wish I could provide feedback about this for speakers that are easier to drive, such as B&Ws, Meadowlarks, Dunlavys and Vandersteens.
Liszt458: please send us your impressions when you're settled in with the 400cx.