First day with CyanogenMod 10.2 on the phone and it's gone pretty well so far. There are a few things I miss from Samsung's UI on Andriod, like being able to drop app icons into folders, but I can live without that. Just means an extra tap and swipe or two to find an app, and I'll need to think about what application icons and widgets I want on the front screens.
Performance seems to be reasonably decent so far, without the slowness and lag I was experiencing before. Could still be from having a freshly wiped unit, so I'll have to wait and see how things are a few months down the road. No issues with any of the applications I've installed yet. Everything runs and overall my Galaxy S2 is much more responsive, like it felt when I first got it.
The battery seems to drain faster, although that could be a combination of an aging battery and me playing with it more because it's shiny and new. Something I'll have to keep an eye on over the next little while.
Moving applications to the SD card seems quite a bit slower. Where it might have taken a few seconds with Samsung's version, some applications took a minute or two before the move to the SD card finished. Not sure what the problem behind that is yet. On the other hand, clearing the application caches can be done with just one tap, which is a whole lot easier than going through each application individually.