Why do these threads always end up in fundamentalist bickering? Almost as bad as religion and politics.
I use Firefox and my wife uses Firefox. My children use MSN (nice shell on IE). Each has their purpose. For one, Firefox has no parental controls so my children cannot use it because I don't have time to overlook their every action and I would like to give more and more freedom automatically as they get older.
However, I will be installing Firefox on all of my retail store's computers. Not as a web browser but I am currently writing a XUL application that will run on top of Gecko so that the inventory of the physical store and the inventory of the online store match. Currently XHTML doesn't give me the richness that I want for my interface but XUL does. That right there is the only real benefit that I see over IE. The other features are nice but not must haves to get work done.