Krell FPB 300cx enough to drive B&W Nautilus 801?

Stevecham, very compelling! The fact that you directly compared both amps in the same system (something I am not able to do) says a lot. It looks like I will be spending the extra money after all. Thanks for the input.

Liszt458: What may have been necessary for Stevecham with his Thiel CS6's, will not be the same for your B&W Nautilus 801's.

His speakers are very inefficient at 86db and yours are much easier to drive at 91db.

Save the money and buy music.

Jtin,
I think what Steve and I are primarily talking about is quality of the power, not the quantity.

Richard

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.

Again, thanks to everybody for taking the time. Very informative! I decided to go for the 400cx, and I expect to have everything in place within the next 10 days or so. I'll let you know how it sounds.