I’ve never had a bad experience flying into the US, had a few where they never smiled, get 20 questions followed by a grunt and my passport handed back and sent on my way.
I hate flying into Kennedy it takes ages to get to the front of the queue, the last time there was only 3 of the desks open, we were nearly at the front when 2 of them just get up and clear off, presumably it was lunch break time, even though no one replaced them for 15 minutes!
The best one was a few years ago, my daughter and I flew into Atlanta and then connecting to Austin Texas. The Immigration guy asked us where we were staying, I told him we were flying onto Austin, he said you don’t want to go there, you get shot there!