I tested also that version with Droid4. Works fine, but screen feels quite small without full screen. Full screen works, but how to get back windowed mode? Current keyboard layout missing F11, but that might no be only problem, because I connected external keyboard and I press F11 and it close Firefox.

I found out that F6 is official full screen button in Maemo (that is what Nokia 770, N800 and N810 Full-screen key send) so if somebody what make Maemo customization to Firefox, it would be good idea.