When I'm just using the internal retina screen, all works fine on jessie and stretch, and I don't recall doing anything special to make it work. Perhaps I used gsettings to set gnome scaling to 2 or something.
On jessie, using one external screen results in the problems I described. Using two external screens additionally results in one of the monitors not working at all (even though the same configuration works fine on OSX).
On jessie, using one external screen results in the problems I described. Using two external screens additionally results in one of the monitors not working at all (even though the same configuration works fine on OSX).