What's wrong with Safari?
Generally, I like the Safari browser. But there are some things that I don't like, and they keep me from using it on a day to day basis. Hopefully some of these answer your question.
1. Silent failure to load pages -- this only seems to happen on computers that are behind some sort of web content filter. Something about it has given Safari a bellyache from v1.0 to the present day v4.0. The only indication of failure is a blank white page. It usually takes a forcible clearing of the cache and cookies to get it going again. Happens on Mac OS (PPC/Intel) and Windows alike. An error message would be SO NICE.
2. Inflexible toolbar -- there's no way to add buttons that I want to have (at least not that I've found). I really like to pop off a new tab by just requesting one from the tool bar, but there is no way to do so in Safari. That "plus" button is infuriating because I think that is what it should do while all it does is make a bookmark.
3. Performance on a Dell Dimension 8300 (that already hasn't been all the machine it ought to have been from day one) with a P4 Northwood 2.8 and ATI Radeon X1300 graphics is mind-blowingly poor. Any redraw of the page being displayed or the UI takes *forever* and drags the machine into the dust. Maybe it's not Safari's fault--I've run it on a Deskpro EN SFF box (PIII/nVidia TNT2) and it was fine. My other browsers work fine, though.