7.10 is an interim release (semi-stable)
This is the difference between opensource and commercial
Commercial - if it's released you expect it to be fully tested and stable - but it usually isn't
OpenSource - if it's released it's mostly stable, but it might have some small problems
It depends which you prefer? they usually work about the same, are about as stable, but one gives the impression it's stable and isn't, and one give you the impression it's *mostly* stable and is ...
Upgrading your operating system never works, Windows, Linux, OSX any of them unless you upgrade a completely clean install with no other software and no reconfiguration...
Games are written for Windows because gamers have Windows PC's that's why games are written for the current consoles, people have them and want games for them, try buying a game for an old console? But it's a vicious circle, games are not written for Linux because gamers don't run Linux and Gamers don't run Linux because there are no games for it ...
Did you try installing the initial release of Vista and upgrading from XP? that would have failed as well, and the drivers for a lot of video cards, WiFI cards etc were buggy or missing