I've posted many times in reports and such about the hassles we almost always go through at the border. However, John has to always enter with a waiver of admisability visa because of what we would term up here in BC as a minor law infraction (he didn't inhale, really!
). Our hassles have ranged from full-on vehicle stripping, 'we're taking you to jail', connecting plane missing, tactics, to a simple wave inside to have a short chat with Homeland Security. I'd add that we don't have these issues entering any other country, just the US.
My neighbour's husband is from Puerto Vallarta. At Christmas they had booked a flight for his sister to come up for a visit. Unfortunately, at the last minute a large hassle ensued because her flight had a quick stopover on US soil before landing in Vancouver. US would not let her enter without a visa that would take up to 6 months to get after applying, even though she wouldn't even be getting off of the plane. What a hassle! She ended up not being able to come at all.