I had one crash with the flash player opening the 770 home page at Nokia. Embarrassing that.

Apart from that, it's much snappier in response. Apps load quicker, videos take less time to start playing and app switching is much quicker.

There are still some e-mail issues - where messages don't get deleted from my 770 when I've deleted them from the server but all-in-all I must concur with Cuckoo, a pretty decent upgrade.