Well I still run a AMD 1800+ on a MSI board that uses that chipset. It runs rock stable and is reasonably fast with a lot of features for when it was released so I see no need to upgrade and dump a gig of memory again.
A freind just built several AMD Opteron 64 boxes, I think they're running at 2 gig but I'm not positive and they soundly tounce his P4 that was his favorite, most stable, and fastest sytem till now. I think he had the 3gig or better in the p4. SO for the moment it appears the AMD is back out front but I won't get one of either becuase I can't justify 4 to 700 bucks just for a CPU.
I will upgrade to a faster CPU my board supports as the prices drop however, then eventually my friend will get the next latest and fastest and I'll probably buy and trade him out of his old Opteron
He builds systems and is a network engineer so we're always arguing the latest things and trading goodies around.