In no particular order:
It looks great, especially configured with fanart
Once configured to taste it is very easy to navigate
Menu configuration is extremely powerful
Upgrade notifications are automatic and it's easy to upgrade from within MP
The StreamedMP team are very very quick to release fixes and it's clear that the skin is extremely well supported
works fine with my 4:3 HDready beamer
For MovingPictures fans it works perfectly straight out of the box, if you use MyFilms it takes just a tiny bit more work to tune, but hopefully there is integration with MyFilms fanart, and latest movies added coming in a future version.
Best skin I've found to date, very happy!