Is it yet worth trying to make the shift from all-Firebug to all-FF-Dev-Tools? I hate having two sets of tools to do one job..
- It uses RGB to show colors instead of hex (I think they are working on this)
- There is no visual indication of margin/padding for the selected element on the page (it is shown in a box inside dev tools)
tl;dr: The bug is on hold until a Mozilla employee comes back from vacations.
I've given up completely on Firefox as a developer's browser ... Chrome's dev tools are better, faster - they don't crash your browser or make it unusable like Firebug.