I'm loving mine so far. Already had a gmail account and google calendar - these synced without a problem. Web browser is nice. There isn't a version of flash player yet but it's supposed to be coming.
The battery isn't too great, especially if you're using Wifi + 3G + GPS a lot. These can be turned on and off as needed to conserve battery. Mine stays on the charge almost all the time. The recommendation is to keep it on a charger as much as possible and avoid full discharges and apparently this will improve the battery life.
Have installed a few apps. Would recommend advanced task manager lite for shutting stuff down, net counter for keeping an eye on what data you use. Record it is handy to remotely set your Sky+, there are several fart generators if you like that kinda thing.
I've been toying with the idea of sending the phone back due to the crappy 500MB 'limit' imposed by Vodafone but really can't part with it now.