One slightly (ok, really) irritating thing about IE7.
Sometimes IE7 will crash nicely... eg, an mshtml.dll error will close IE7 down quite nicely.
ntdll.dll, on the other hand, is a different story. You will need to acknowledge an individual crash report for every single flippin' tab that you have open... if you have, say, 20 tabs open, that gets real old real quick...
Word is CSS is way improved in the Mix06 build of IE7. Check out what Molly had to say. I'm looking forward to seeing public reaction to that build.