I just upgraded my new desktop which came installed with Windows 7 Home Premium 64 bit with a copy of Windows 7 Ultimate 64 bit and so far I have not noticed any difference in performance. Even my Windows Experience Index number is the same 5.5 that it was before the upgrade.
So what's the point, are there any performance advantages that I'm not seeing?
My system hardware specs:
AMD quad core 2.6 GHZ 1 TB 4200 RPM HDD 8 GB DDR2 RAM ATI Radeon HD 4650 w/ 1GB dedicated video memory