I switched to VimFx so I could get electrolysis working. I had to tweak scrolling speed quite drastically and and there are some behavioural differences which means I have to unlearn some muscle memory. However, with the classic theme restorer addon the UI is compressed enough that it doesn't bother me much and I can use the keyboard for almost everything.

I still wish I could have the command line back though. Annoyingly Firefox actually includes some sort of command line thing when I press :, but it seems to be only for web developers. I'd be happy if Mozilla provided a way to extend that so that it could be used for actual browsing...