As a New Yorker, I think it may be appropriate to comment here. (New Yorkers often carry the label of complainers, for those who do not know the stereotype).

If things are good, with a few bumps, don't complain.

If things are good, with a few problems, point them out.

If things are bad, absolutely complain.

If you don't complain, IMHO, things don't improve. And there is a lot of service deficiency out there, both in the US and abroad. Having said that, I am mindful of the rules of the game while abroad. But a few careful words usually gets the problem solved regardless of location.