windows 8 frees up much more RAM and CPU then windows 7.
it kind of breathes new life into your computer.
before you upgrade, make sure to run the compatibility checker.
heres the link for that.
http://www.microsoft.com/en-us/windows/compatibility/CompatCenter/Home
now my opinion, i loooooved windows 8, and then windows 8.1 came out. although installing windows 8.1 was kind of a hassle, it was sooo worth it. it is awesome, very snappy.
search is awesome.
gaming is great, i haven't run into a single problem and i play to many games. haha.