What's to be gained from observations?

Luck of the draw, because of first a practice inspection to prepare us for the possible real inspection, then the real Ofsted, then the inspections that were due anyway, then the obs through HGSI, I've been observed a terrific amount this year, and what have I gained from it?
I observed one lesson from my mentor, Julia, and gained more from that than the lot of the obs. I got to see a different approach, a different feel, different level of formality and how the whole thing held together - which was very well - but the observations were a different matter.
The observers aren't really watching you teach, they're watching you deliver an observed lesson. It's not the same thing. It's like watching a waiter, perfectly adept at carrying four plates, spin eleven on sticks.
No-one teaches, prepares or writes lesson plans for an obs the way they do for a normal lesson. Some teachers get great obs results because of the time they spend preparing, but the rest of the time have poor retention. Obs are a exhibition. Perhaps I'm being obtuse but I don't think I got a thing out of the whole lot of them. Observers, with too many boxes to fill, tend to make obtuse observations, like 'the room is too small, the board is dirty.' Sure the board is dirty, the cleaners don't have board cleaner. Yes the room is too small. Why don't I have the college move to handsome new buildings.
Teachers are always assured that it's only the teaching parts of the observations that apply to them, but the grade is overall. It's less a measurement than a stick.
Do I sound bitter? Probably. I am.
I love it in the classroom. It's a happy, creative, functional, purposeful place with a whole group of people all pulling the same way. The staff room and college management are an incompetent self-serving bureaucracy. Most FE and HE institutions run for the benefit of faculty and staff with education running a poor second. If you doubt this, look at the pay structure. As teachers drop teaching for management, their pay rises.
Observations are an unwelcome intrusion of this bureaucracy into the classroom.
I'd rather drive a van.
I own a van.
Hmmm.