While I haven't gotten to downloading the beta on this machine (and it did turn up in Software Update last night on the Powerbook, but didn't have time to install) I have been using Safari almost exclusively for quite a while now. I still have to fire up IE on the odd page that doesn't work in Safari, but also have Camino, which is also very good, Mozilla, Omniweb...the nice thing about X is there is no shortage of good browsers!
My absolute favorite feature of Safari is that little Google search window on the menu bar - I use it all the time and find myself irritated at its absence in IE, when I go back to it for any reason. Horrors - I have to actually click on something to change the window I'm in (google lives in IE's toolbar favorites on my machines) Is that the height of laziness or what? ...it's always the little things!