Firefox is better because there's competition from Safari and others - that's great, because it means that normal people can find the software that works best for them and make their own choices. Firefox 3 is an incredibly great browser, I think, and competition has helped that, resulting in things like our amazing memory footprint and the incredibly useful AwesomeBar and literally thousands of other improvements.
As a consumer, I want more competition. I want things like mint.com to put pressure on Intuit, for FriendFeed to put pressure on Facebook, for Netflix to put pressure on Blockbuster. And for other browsers (like Safari) to put pressure on IE, and, yes, Firefox. And I want competition in my role at Mozilla, too - competition makes everyone work harder to listen to what people are saying about what they want, and to work harder to deliver something that is great.