I use a mac, and I have firefox, but I don't use it for much more than testing my site's compatibility. Safari gets the job done. The new features in the beta are nice, and hopefully everything will be much more smooth when the final product is released.
Unfortunately, the windows version of the beta, from what I've heard, needs a lot of work.
Safari is (eventually) for people who want hassle free browsing that works, and not so much for geeks who want to control every byte of data that comes through their network connection.
The only problem is that people are still designing sites to work primarily with IE, and have very little to no consideration as to how their sites work with other browsers. When I create a site, I'll make sure that my code validates, and that it works in Safari and Firefox, but if there are things that don't work correctly in IE (things like CSS), I'm not going to bend over backwards to "fix" my site just for microsoft's crappy browser.