Haven't been able to find many (or any really) games with incompatibility issues. Even so, running them in compatibility mode works great when things like that are buggy. I did find a few pages with lists of incompatible games, but I tested a handful of them and was able to run each one easily.

The OS feels really fast and smooth to me. Apart from a couple customization bits that I feel will be available in the future, it definitely feels a step ahead of Win7. Over coming months, we will see if it lives up to its predecessor's stability.