IE 7 is a FF and Opera rip off Microsoft made it just to stay ahead, i think IE still sux and it'll be still a security risk like all Windows software is
I just started using FireFox last week after using IE since about 1998 ... and I would have to say that FireFox is better than IE but not as much as everyone is saying. I will use FireFox now, cause I like it better and it has many more features. It's just not a million times better than IE. I'd give IE a 7/10 and FireFox a 9/10