After submitting yesterday's Firefox 3 vs. Windows Vista post, I uninstalled all the extensions I had previously installed in Firefox 3 RC1 to see how it behaved. I must admit, I do miss the glass effects from Glasser and being able to hide the menu bar. But with the understanding that 24 hours does not a data set make, I can report that Firefox 3 is already dramatically more stable. I haven't had a crash yet since I removed the extensions.
I'll give it a few more days before I declare victory, but that's a good sign. Maybe I can get my Vista reliability index back up in the 9's while I'm at it. :)