I have been using AX-7 for a month now with both A7V266E and A7V333.
I was getting 47C idle and 54C (room temp is about 27-29C...I need airconditioner!!!) fully loaded with stock HSF.
temp drops 8-10C after putting AX-7 with 80CFM delta fan. However, it is a very loud fan (plus I put 8 80mm-92mm fans on case and 4 other fans on AGP and mobo). My wife complains so much. I then bought rehobus from PC Mods. It is a very cool fan control device (4 channels and all can handle 17W load). So, I can use the full speed when I use intense 3D application and quiet it down when doing web surfing.
AX-7 is one of the top prformers for air cooling. It needs quite a bit room to fit though. A7V333 is a very nice choice for it.