Mono 909mk5, then stereo 909mk5, then mono 911mk3's, then stereo 911mk3
You are correct here - best sound of all of them are mono 909mk5 and then stereo.
I like the sound of 909mk5 stereo much better than mono 911mk3 - the very big transformer and better quality parts has something to do with that.
Thanks, Joe and Wizard! Great to know. Will keep that in mind if I ever get a chance to hear Burmester.