I use Safari exclusively, and that was the source of various problems, for on two different computers, it has a number of annoying problems that FireFox does not have. The most important one is that none of my content was updating, and I was becoming quite frustrated, until I switched to Firefox. In the Editor, it was impossible to select all of the copy, and it would never save anything that i typed. A number of text widths also ran over their border.
This alone made me wonder how Joomla, your excellent templates not withstanding, was going to work.
What I miss is the built in spell checker, but the joomla site has one built in that impressed me.