You aren't the only one, the game itself plays fine for me but the menus have MASSIVE performance issues for me currently (1-2 seconds of hangtime between clicks), but thats to be expected with a beta I'd think lots of strange performance issues gonna start showing up.
From memory vid card, processor and memory for my machine are as stated below:
Vid Card: ATI Radeon HD 5700
Processor: AMD Phenom II x4 955 Processor (4 CPUs), ~3.2GHZ
Memory: 8192mb Ram