I've just spotted than when maximised the new Firefox button in Firefox 4 is positioned like the image below; with the Firefox button, tabs, tab group button and min/max/close buttons all sharing the same horizontal space:
But I have a wide-screen monitor and so don't keep Firefox maximised - I keep it open over the right 60%, or so, of the screen - and when the window isn't maximised, the button is positioned as per the shot below, which consumes more vertical space, and now that I've seen the more compact version, I want the more compact version all the time.
Is there any way to utilise the "maximised" button and tab positions on a non-maximised window?
The closest thing I've found is the Movable Firefox Button add-on, which changes the button's position but doesn't recover the lost vertical space, so (I think) actually ends up looking worse than the normal version when not maximised...