I'd use both, though primarily I'd use Internet Explorer. Both are good, I think.

I don't like Safari. I know it's just Beta software, but I don't have high hopes for it. The metal colour sticks out like a sore thumb. You also can't "Tile Windows Horizontally/Vertically" with it, which is a pain. And the default text that it uses isn't as clear as Firefox or Internet Explorer. And it's also vunerable too.

Rant over.