i will actually always recommend using Firefox Developers edition , especially if you have a x64 system, because they have a x64 firefox (which is way faster) , 2 suggestions though,1 disable auto-update completely, because at times it breaks some add-ons, 2 actually disable the multi-process feature, or when offered to test it say No, thus far it's very buggy and it renders a lot of add-ons useless.