Thanks for the roundup. It's what I came here looking for. I've used Opera 12 until now, but I've been experimenting with the javascript File API, and FileWriter it isn't supported until 15.
Chrome hasn't improved at all since I last tried it. There's a new mouse gesture addon, MouseCrx, but it too misses about 2/3 of all gestures. Firefox does not have native mouse gestures, but FireGestures has worked very well. Firefox even has a bookmarks pan... uh, sidebar! No support for File API, but it's time to update, so I'll stick with it for now.