Mozilla is nothing if not honest.
The newest edition, ff4 is very fast. I prefer Pale Moon because I find it faster on my system.
We’re all in it for speed, security, rendering and stability, truth be told.
So, which are the add-ons that really slow you down (by significant amounts)? Thake a look, especially if your browser is not meeting your expectations regarding speed.
The article (and expandable table) are here:
https://addons.mozilla.org/en-US/firefox/performance/#addon-11
I find it ironic that “FastestFox” slows you 33%, and AniWeather by 54% is a shocker.