furnace said:FF is also far better at rendering web pages according to the "Acid 2 test"
I have two problems with that statement. Firstly, the current version of Firefox doesn't pass the acid2 test. Whether it does it "better" is completely arbitary and seems to be your opinion. The test was designed to be a pass / fail test, not something that can be scored, and as such I don't see how Firefox (current version) is any better than IE 7. In particular, the most obvious difference between the two pictures you show is the red / white background, which is a fairly minor thing at the end of the day.
Secondly, you assert that its performance in that test makes it "far better at rendering web pages". It makes the pre-release version of Firefox better at meeting standards and better at passing a very contrived test, but in terms of real world pages I think this is entirely irrelevant. Both IE7 and Firefox display most pages well. The only time I've ever had an issue with either browser is either when developers have been incredibly lazy or used outdated tools, or where someone has foolishy set their server to check the user agent string and refuse to serve a particular browser. Some firefox enthusiasts are terrible for this - seeing a page in IE7 that tells me how much better I'd be doing if I were using Firefox is very irritating and, I would have thought, against the whole spirit of making a better browser.