Windows 7 or 8 - Mining Purposes

So I was going through and reading some of the "benchmark" statistics for a lot of different GPUs for mining Bitcoins & Litecoins, and a couple of them said they hashed better running Windows 8 Enterprise. Does anyone have any experience with mining on a Windows 8 system?

Trying to determine if this new mining rig I am building here in a day or 2 should just run Windows 7 or Windows 8, so I would really love to hear all of your feedback on the matter. Don't want any headaches (cough...8) but would love to get the most performance I can out of my mining setup.

 

Also side question, I have a 1TB drive from 7 months ago, has all my old files and OS Windows 7 on it, can I plug that into this new rig and see if it will boot? Or will it need to be formated and start fresh. Just wondering. Thanks guys.

I Bitcoin on Windows 8 with a 7950 Oc and get about 630ish mhash. I doubt the OS helps tho. Also yes you can use that HD without format.

Alright well if that is the case, I may not install 8 cause I have 7 on it.