Looks great, performs better. Best feature: super-powered search. Next best feature: global inbox.
Lightning doesnâ€™t yet work on it though, so I canâ€™t move my main work machine to it. At least Enigmailâ€™s OK. Canâ€™t waitâ€¦
Update: broke down and installed TBird 3.0 with the Lightning nightlies. Working OK so far.