No.
I have compared a 920@4066 (aircooled and 24/7 stable) with a 3800+@2510 Mhz in 7 different applications and benchmarks (DVD Shrink, LAME, Cinebench, Photoshop, Business Winstone, PCMark 2005, WinRAR) 4 different games (FEAR, CoD, Quake, Battlefield). The 920 was in almost all of them...