Accepted the "suggestion" to upgrade to 29.0.1 which was to be just a security update. Didn't realise I was at 28 and that this was far more than a security update. Spent a few hours undoing the UI changes, installing the "classic theme restorer" extension and then within it, having to play with settings. The one thing I was not able to undo: grabbing anywhere in the top bars (not just the title bar) causes the window to move. Fairly annoying. (on my machine, a slight move of a window causing it to overlap into the adjoining screen causes major performance degradation). Is it normal that applications can designate areas inside the window as grabbable for purpose of moving window ? I thought this was limited to the title bar. Or is this a case of Firefox creating a huge title bar, and faking a real one inside (it can be removed, and in fact is removed by default).