FF 7.0a2 (got Jul 24 from the Aurora channel) is less responsive than FF 3.6 was on my machine -- although I cannot be sure that the unresponsiveness is due to memory pressure rather than, e.g., insufficient parallelism of the UI relative to the part that executes Javascript.
I think you can help them in this -- they're starting to gather UI responsiveness metrics. If you're seeing especially bad UI lag, they'd probably like you to run those metrics to help them figure out what is going on.
Disabling hardware acceleration (it's in the General tab of the Advanced pref pane) seems to have solved the horrible problems I was having with Firefox 7. Thanks!
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 ;)
https://bugzilla.mozilla.org/show_bug.cgi?id=666058#c31