The one thing that keeps me from using Safari is web apps can't update their tab's favicon. That means if you load a site that uses the favicon for notifications you either (a) login when you have a notification and it will now forever seem like you have a notification or (b) login when you don't have a notification and it will forever seem like you don't have any notifications.

Yes, you can clear a cache for a one time update, but that is hardly helpful.