FWIW - - - - I've always used IE from Day One. Always worked fine for me. And given that I'm from the "If it ain't broke, don't fix it" school of thought, I'd never diddled with anything else. But based on this thread, I thought, "What the heck?" So I downloaded Firefox 4.0 Beta...........and it absolutely leaves IE in the dust performance-wise! I get much faster responses, screen loads, etc. Makes the machine run like it's got a new fancy-schmancy processor or something! I'm a happy camper!
Just my experience - yours might differ!
Bill