Hi Leon,
I upgraded to win8 on my lappy a few months ago with absolutely no problems. It's very fast and stable and every program I use works as well or better than win7. I've heard there are a few programs/hardware that require drivers that haven't been updated to win8 yet but I can vouch for: CS6, Lightroom 4, Startools, DSS, Registax, PHD, software and drivers for my 5DmkII, Atik 314L+, QHY5L-IIc, plus all the usual browsers, music players, utilities, etc.
I did get a start menu as I prefer that way of doing things but I don't hate the Metro thing and I do use it occasionally. TBH I'm not sure why people complain about the new start screen, you just press winkey+D and you're on a familiar desktop or you can set it so it just boots straight to the desktop.
My $0.02
