Bonjour Amigos, Just upgraded to Windows 8 Pro on the following machine: (Just look at the spec).
It was a very seamless and easy installing, however my version of Kaspersky had to be un-installed as it was not compatible with Windows 8, apart from that everything else worked fine. At first it was difficult to use as navigating around the desktop (app) without a start icon is confusing...
Whenever you press the start key you are redirected to the new Windows start screen! It can be quite confusing at first but intuitive minds can get used to it quickly. For example, if you wanted to search for an application or file, you carry out the same action you would on Windows 7 START + 'app name', however it looks completely different:
This concludes my analysis for upgrading to Windows 8, just to summarise I would recommend upgrading!