I know this had been asked before acouple of times but that was way back in 2012 and 2013...
Anyway: what I'm still missing is a way to collapse the tree(s) in the left panel with one click (e.g. via context menu). I already wrote an autohotkey script to do this and it works actually quite nice (although it takes half a minute or so) but not everyone uses AHK and a buil in function would be a nice addition I think.