There are two things about Windows 8 that I hate, from a technical standpoint.

1) DirectDraw emulation is further deprecated. They are getting rid of emulation that allows you to run games which are dependent on ddraw.dll. The last DirectX package DirectDraw was part of was DirectX 7.0. Since 8.0 it was merged with Direct3D functions and stuff may break. However, until Windows 7, emulation usually did a good job (barring for the occasional color palette problems).

The bottom line is, if you want to play pre-DX9 games, you have to stick to Win7.

2) No more 16-bit color mode. Win8 is all 32-bit color, the rest are emulated. I remember when I was playing with the developer's preview version of Windows 8, it had a ton of problems with emulating a smaller color mode. Nowadays it's not so bad, but if you like playing games that are 16-bit color mode only, stick to Win7.

I honestly don't think Windows 8 is a bad system. It is lighter than 7 (although clogs up the same as 7). The problem is that nobody thought it thoroughly - you CANT change the entire flow of a system overnight and expect users to be ok with it. And Microsoft did. And got their butts handed to them on a platter.

There are some people who like Metro - and if you don't install too many programs, the All Apps section of metro isn't badly cluttered and it can work alright.

My final advice however would be to get Windows 7 x64 in a boxed version, because Microsoft is starting to pull a plug on them - I can't find them in internet retailers in Poland anymore and on ebay/allegro (polish ebay) they are ridiculously expensive.

Have you tried XPMode?

Also, I use Oracle VM at work for some XP related tests ;) Funnily, with Guest Additions even The Witcher Adventure Board Game ran very satisfactorily, to my surprise.