I use Intel, but I will not go the P4 route due to the limited life of the current design.
Once Intel settles on another bus design that will have better shelf life, I will then look into them again.
P3's are getting cheaper and the the chipset support is still better than the AMD processors have (sigh).
I know many will jump in here and claim to have no problems with the AMD support chips, but I consider not being able to reliably run AGP 4X speeds a problem.
I also have a rather unique environment. All our systems have to be able to be servers in a heartbeat. For this, Intel gets the nod, as UNIX just works better and more reliably with Intel support chips.
This does not mean I am a fan of Intel. Quite the oppposite, I hope one day AMD will get a 100% compatible suport chip solution so I can move away from Intel. Until then, I am stuck.