If you don't have a 50" touch screen, there is no reason to use Win8. It was intentionally hobbled by the MS design team so that people who used it would want to buy MS phones and tablets that use a similar UI.

The back end is pretty quick though. If they ever put a Win7 skin over it, I'd consider upgrading. 3'rd party apps that make it work more like Win7 are suboptimal because programs that mess with the shell tend to cause more problems than they solve.