10540
interesting comments but in my experience treating each person as an individual is a better approach, regardless of age. I taught a knighted chairman of industry who at the time was in his early 50s and there could not have been a nicer, gentler character but I can think of a few 18/19 year olds that caused many problems, especially in the 'know it all' department! (sadly I had to bury one)
Again with instructors we had very experienced ex RAF transport command instructor, total disinterest and an appalling instructor just ticking by till 65. When all of our instructors were checked by CFS for cadet training the only one out of 8 who they wouldnt approve was the one with the highest hours, a BA 1-11 skipper.
scathing piece denigrating business/prof types who turn up in a BMW with an attractive "blonde" woman companion
Thats just jealousy, a common human trait(just look on here). The one thing you need to be able to deal with as an instructor is the amazing complexity of human factors!
Spotting good instructors as you say is difficult when you start out and this is used by many poor instructors to their advantage EG if you are nice to the student, give them a really easy time and allways tell them what they want to hear they will think you are a great instructor. You cannot determine who is a good instructor until you actually first fly with one!