Conkeror is the browser you want it to be. It replaces Firefox's overly complicated extension mechanism with something that's a pleasure to use. Great for hackers who don't mind getting their hands dirty writing things like more efficient buffer switchers.
I like that everything is hidden -- no toolbars, menus, or tabs. If you already know emacs, you don't have to learn any of the keybindings. New to Conkeror? M-x apropos-command help is all you need! My only suggestion, embed this in emacs!