Not a fan of how Opera handles a lot of things. Love it for the one time I needed a full-screen browser on Mac OS (FF & Safari can't do it... stupid shit), but it absolutely sucks when trying to use most Google web apps - just doesn't do things properly.
I'm also frustrated with Safari. Chrome is nice sometimes, but I stick with Firefox for the most part - had some freezing issues a while back, but created a new profile & things have been fixed since then. Try creating a new profile & readding your extensions - see if that helps.