Ex-military - their instructional technique & style is second to none.
However, the instructor i flew with for my PPL is also top dollah and i wouldn't have changed him for anything else.
I think its all down to personal opinion and the instructor in question - each has their own taching style based on the same syllabus, and its what suits each individual student; as one may think 'X' is a fabulous instructor, but that instructors technique, style and of course personality may not be what another student likes or wants.
I don't think there is no right or wrong answer, but everyone is entitiled to their own opinion, as everyone has had different experiiences with inistructors from a variety of backgrounds.