Been trying to use it fairly consistently, seems to be doing fine. Not been using it exclusively, since I've actually been looking at stuff elsewhere, but when I've been using it for myself, I've rarely felt the need to switch, thus far at least
This has been my experience. A lot of my daily searches are navigational and it's great for that. Informational it is pretty good - I mean it can give me the Wikipedia link just as good as Google and not be logging it so - Win!
Deep information, and shopping/info type searches it is not as good as Google. A lot of spun-content sites make their way into the SERP's - more than Google. But I'm not getting a bunch of Google internal sites so there is a tradeoff. I really need to test verses Bing.