Firefox .9 is a lot leaner than previous versions, it doesn't make sense to stick with .7 as it lacks some features. It may work for you, but I find .9 works the best yet.
I tried Opera, but never could get used to its clunky interface. I also used MYIE2 for a time, that is until Firefox became available. There is no going back, except for the WindowsUpdate and occasional problems with IE specific sites. Still it works the best for me and if MS cares about IE they sure don't show it. I want to use a program that has people working on it.