All HTC phones are skinned too, although I actually really like the functionality the 'Sense UI' adds.
You can easily remove such skins anyway. IIRC correctly, you can just uninstall it.
I've got a HTC Desire, and the calendar with the Sense UI is brilliant. It syncs all of your Google calendars and I love it.
Battery life is an issue (as it is with all data heavy phones). If you leave the data connection always on, to take advantage of push email and seamless syncing, then you will need to charge it every night.
But if you leave that function off, you'll easily get 2 days out of it.