Earlier quoted context omitted.
Firefox has made memory overhead a serious priority in the Fx7 & Fx8 development cycles, with some impressive results: https://bugzilla.mozilla.org/show_bug.cgi?id=666058#c31
Too little, too late. It took them literally years to admit that they had a problem. I've long since migrated, and I know many other people that have as well.
For me, I try Chrome out very often but keep coming back to Firefox because of the fantastic extensions, and because it just feels right in a way that Chrome doesn't.
But that's OK: I'm assuming you've migrated to Chrome, and that's a very good thing. The competition between Firefox and Chrome has only served to make both browsers better.
Two open source browsers with a significant user base? In 2001, we only could've hoped to be so lucky ;)