All of these things have been working fine for me, and unlike many people, my experience is consistently that Chrome has significantly worse performance than Firefox. That said, I cannot remotely condone the removal of Xul without a firm commitment to either replicate functionality or a firm commitment that it will never happen, publicly. I love pentadactyl and Vimperator, and the idea that they may get killed permanently is infuriating, but not as much as the fact that the wiki page on that functionality has gone dormant.