This is kind of the feeling I have too. I remember firefox in the 2.x and 3.x days when you could do practically anything XUL and XPCOM. I also remember that firefox was dead slow back then. Although I am kind of dissapointed that so much functionality was removed it is inevitable that, in order to get a better and safer browser, some inconveniences are to be expected. I wish there were some kind of middle ground to accomodate power users as well. But Mozilla is not after power users, they can't afford it. It is kind of a shame though.