Can only speak for myself as a IAM Observer - with a 100% record of my associates getting a first** (Yeah baby!)
**Before you get too excited - that is 1 associate - as I only started observing 4 months ago. So clearly not the TC level of insight!
My (very limited) take it on it is thus: IAM or Rospa - way more depends on your observer. Some are knobs, some are brill - who knows which will you will get? When I did an intro session I liked the guy - so insisted on getting him. Didn’t want a knob.
As for speed - my take on it as an observer is simple. You will ride as fast or slow as you want / choose. I am not going to worry - that’s your business / your life / you decide how fast you wish to ride. But as an observer - I would like to help you ride as safely as I can. So if you do ride fast, I’d like for you to do that with safe lines / anticipation / judgement etc. If you ride slow, I’d like for you to do that with safe lines / anticipation / judgement etc.
If / when we are out - if you are giving it plenty in the 30s, for sure, I’ll sit back and let you go. In the nationals, am going to be way less worried about it.
But if you are significantly over the limits, I’ll point out that you risk your license but in itself I wouldn’t go over board if I didn’t think it dangerous. We are all adults and make our own decisions. That said, if I think your riding (note I didn’t say speed) is genuinely dangerous, I’d not hesitate in saying so.
I’d also point out that on test, you are expected to ride within the law at all times. Though there is defo some flexibility given that an examiner (TC?) would not fail you for doing 61mph - rather he’d assess you as if he was on the road and give you some leeway (as I understand). That said, on test doing three figures in a 60 probably would lead you to fail.