The retirement visa options seem to be well 'proven'.
It would be a shame for a 'retiree' to come unstuck after switching to what is essentially a glorified tourist visa... It's probably fine for many 'retirees' but only time will tell, I suppose...
The system varies from country to country, but basically you walk up, insert your passport, look into the camera and if all the checks are ok, you go through.
No officer. No stamps.
Thailand has had them since 2012, but they're now being rolled out for use by everyone who has an e-passport, which is most of us these days.