Have a 12 week old who tends to get hysterical when overtired. I now put him down in his cot the minute he starts giving tired cues (or 1.5 hours since his last nap, whichever comes first) swaddled with dummy in dark room. This usually sends him off really quickly but he does sort of grizzle for a bit first. Whenever he makes a sound I go and stroke him to calm him but I don't pick him up. If he starts crying I stroke and talk to him but again don't pick him up unless he gets totally distraught - the reason being that he doesn't actually want picking up most of the time, it gets him more overwrought. But I am always there, responding to him.
Saw SIL this weekend and she witnessed me putting him down for his naps and said she thought it was cruel to do cry it out and I should be rocking him to sleep. I told her he won't be rocked to sleep unless he's literally demented with exhaustion (and I try not to let it get to that point!) and this is what works for him. But she wasn't having it.
I would happily hold him and rock him all day if that was what he wanted. But AIBU to think a) all babies are different and b) letting him grizzle a bit without picking him up is not the same as letting him cry it out???