I opened my Firefox after a few months and upgraded it to 9.x just to see what Microsoft have achieved. Great work indeed but I'm not sure it is worth changing

I opened my Firefox after a few months and upgraded it to 9.x just to see what Microsoft have achieved. Great work indeed but I'm not sure it is worth changing and messing the CSS standards. Some of them were already achieveble by doing a few tricks like using different fonts IMO.