How do you feel about Firefox 3.x.x?

Ever since I updated my Firefox from 2.x.x to 3.x.x it has been crashing and acting weird. Sometimes it’s really really slow and just freezes, IE works fine (I only use it as a last resort while FF is restarting) and Chrome is fine also.
Should I go back to 2.x.x?
I just know it is ONE guy who is responsible for this, one lousy line of code or character… >:(
I delete the Temp files, delete/empty history/cache/cookies etc. and disable all the add-ons/themes etc. but it still does it, my Firefox hasn’t been the same since the 3.x.x. update.
What has been your experience.