I have been running the beta. Speed seems lower than normal (9.7 instead of 10.1 Mnodes/sec, but they fixed the stupid crashes that made me dump the 8012 client weeks ago. Perhaps after they take out some of the "beta clock watching" routines, it will speed back up.
It seems very much oriented toward RC5 in the menus.
Jay, I don't have a P4, so I'm really not much help on that. It is stable, but it looks like the same cores.