olster in particular - I've been an instructor for 13 years now, recently "upgrading" from CRI to FI, flying for around 33 years, and doing checkouts in interesting aeroplanes for around 20 - it was a huge relief to me when I first formally trained as an instructor to realise that my prejudices that a formal brief and debrief, and clear structure to an instructional flight were actually reinforced by the instructor training. I've also had those flights where I turned up, briefing was extremely minimal, went straight to the aircraft, and the instructor rushed stuff that really shouldn't be, or conducted things that weren't briefed.
No shortage of other bad practices I've seen whilst being a student too - I'll bet you all have too, so I don't need to detail them.
I'm totally relaxed about *how* a CRI or FI course is conducted, for me or anybody else, so long as it delivers instructors to test and thereafter with the skills and inclination to do the job properly. Ditto most other training. However this "skills and inclination" bit should never be negotiable, however delivered.
G