I made a video review of a MIUI costum ROM. it uses android 2.3.7. and 2.6.32 Kernel.
It is very smooth, fast and quite stable. Only volume maker and asdp manager crash from time to time. It has no menu/application window. all applications are on the home screen. You can create folders for better organization. Menu/settings is totally different, U will get used to it. I found it very nice.
For installation you will need:
1. Rooted phone - i used Z4Root
3. MIUI Zip file