Maybe against IE 8 FF is the superior browser by far but you have to be kidding me that FireFox, a browser I use extensivly, being by far superior. In fact it’s the most buggiest, crash ready, memory leaking, web page mis-rendering browser I use. IE7 just happens to be slower than FF in most tasks but as far as widespread support and memory usage IE7 owns FireFox 3.0.1 and lower.
I have had the crash issues you describe with IE7, although it has gotten better since its initial release.
I would disagree with FF being the problem with web page rendering.
If a site renders correctly with IE and not FF, there’s a good chance the site designer was very sloppy coding the site.
It’s very possible to code site that will render properly with IE, yet will not render correctly with FF.
However, I have yet to run across a site that renders correctly in FF, but does not render correctly in IE.
Personally I love Firefox, it's stable as can be for me, doesn't exhibit memory leaks, and works just great, much faster than IE7. That said, it doesnt work at all on my wife's computer. It blocks the CPU for several seconds periodically. Just locks up the whole PC, runs at 100% CPU for no good reason. I've run it with no plug-ins, tried every fix I could find by searing for "firefox 100% cpu" and still it does it. So she cannot use it. So it works perfectly on my laptop, not at all on her PC. Perhaps you have an issue similar to hers, whatever it is.
I’ve never had any of those problems with Ff. The worst I’ve seen is slow load times on XP because Ff doesn’t “TSR” like IEx. Vista and Win 7 don’t have that problem because of Super Fetch.