Firebug 3 aims on bringing back the same dense and concise UI of Firebug 2. The DevTools team is also working on
closing gaps between Firebug and their DevTools. You can
read in the Firebug blog why the Firebug Working Group decided to built upcoming versions of Firebug on the DevTools.
A general 'hardly different from pretty inconvenient Chrome and FireFox tools' doesn't help to improve it. So feel free to
report any specific missing features or UI changes you think need to be improved and are not filed yet.
Sebastian