In some of my early tests Vista 64-Bit SP2 and DX11 patch outclassed Windows 7 SP1 in performance on the same configuration.
It's just the drop of support of Vista that is now hurting it otherwise it will perform better compared to W7.
I should probably add I had initial Vista resentment but that is because the laptop was too underpowered to really appreciate Vista and on XP it flew. I really dislike the Pin To Taskbar in Windows 7 vs Quick Launch/Clear Desktop and even Vista is missing some of the nicer features of XP but it's a shame MS doesn't give a d*** about keeping the old user interfaces so people still have a choice instead of making everyone relearn a completely new OS user interface.