Wine for games is still a massive crapshoot. Firstly you will get compatibility problems with many DRM systems which is a killer if you plan or running your legally licensed games without cracking them.

Assuming you can then get the game to work , expect graphical glitches a plenty , occasional/not so occasional crashes , slower performance and issue with the audio and visuals being out of sync.

There are a bunch of older games (GTA3 etc) that work fine in wine, and some indie games that have been built for it to begin with but I couldn't recommend it to anyone as a gaming experience that is close to that available in Windows 7.

Completely agree with you. If you are a gamer, the only solution is Windows, there is no alternative.

Steam on OSX brought some hope, but performances are just not there yet, and in any case, as long as developers will stick to Direct X, there won't be any other choice than having a Windows installation. I cannot blame them, Direct X seems to be largely above OpenGL, notably accessibility wise.