I would upgrade to windows 8 because it uses less ressources than 7. The start screen can be fixed by installing a third party software that brings back the old interface.
The problem with 8 is that some games don't work well on it. There aren't any drivers for older hardware and you have to reinstall all of your crap.
That's kind of how it goes with all Windows versions, even if you like it you better wait a bit, so your crapton of "old" stuff doesn't get screwed over, or at least until there's enough info about what gets screwed and what doesn't.