1. Looks like the Precision Zen stock one (or clean like it)
2. Has the calendar show appointments in the home screen
3. The Calendar shows Facebook events (with FB v1.5)
4. Doesn't slow down the phone!
Interesting, I have FB 1.5 and a today extra home screen but FB calendar events don't show up on the home screen view [only in the calendar app]. I've checked all the settings and it doesn't appear to work that way.