I havent use much 7 after I installed 8. I have Dualboot system Windows 7 home 64 bitt and Windows 8.1 Pro. I buyed Win8 when It came and after using one month, I forget Win 7. Reason better file management, faster file system, better memory control etc.. So much neede thing under the hood versus Win 7. Some games even work slighty faster.
Windows 8 is just another version of Windows 7 designed specifically for Tablet PCs or the Windows Phone. Unless you have a Mobo with the 6 GB/S throughput for external storage devices (ROM, SSD, etc) you will see no real performance increase... whatsoever. The File Sys is the same, File Mgmt is the same ( or lack of ), memory ctrl doesn't matter unless you have good RAM. It's all about the Speed of your RAM vs what your board can handle, that said, the OS doesn't even really matter as much as:
1) What your board is made of
2) What your board can do
3) What hardware is on your board
If you do not have that 6 GB/S throughput, it doesn't matter what version of Windows you have it's still going to take a while to load. Why someone would want to install a Tablet OS in place of Windows 7 is beyond me. Unless you have a Tablet PC w/ a Touchscreen, Windows 8 is unnecessary and can't do some of the things that 7 could do because they've locked it down. But I can't really talk about that lolz.