If you like the backend functionality of Firefox you should know that you can change all the chrome to fit your tastes, most specifically nuking the status bar and moving the page load progress indicator to the URL bar. Changing to a different icon is about a 5 second job in OS X.Using it now, seems very good. I prefer Safari though, it blends in better on my dock, the FF icon just sticks out. Also, Safari's toolbars don't take up as much space. Firefox just looks bloated to me on the Mac, and I use it on my PC desktop + laptop.
Mmmm, I think that KHTML is still faster, especially in JavaScript rendering, but Fx3 brings the gap much closer together. For me Fx is able to do so much more that it would be silly to switch over to Safari for a few percent increase in speed.Have used it since beta. It's good, quicker than Webkit and less of a RAM hog. Looks good too.
Much better than the buggy RC3 version that I had been using, scrolling now especially seems much more fluid
Love it!