I'm from the South so I hear it a lot. I try not to mind it unless it's obviously patronizing or degrading (condescending is the word I was looking for here). My older brother has a way of using "sweetheart" that will set my nerves on such an edge they're sharp enough to cut heads off.
I feel like if it comes from a woman I don't mind it as much. If a man says it to me my hackles go up.
I think I've used hon here before. H and I use it all the time for each other. I wouldn't use it with people I don't know or at work, and I wouldn't expect to be called hon or honey in those situations either.
I don't love it. Extra annoying when the person who is saying it looks younger than me. But I also don't want to be called ma'am. So I'm just hard to please.
California checking in - I like the way it sounds when someone is being comforting "Oh honey, I'm so sorry!" even if it's not a close relationship. I'm going to go with diner waitress with a southern accent being okay - otherwise, it would strike me as definitely odd and probably condescending.
I grew up all over the South, so I don't even notice unless I'm in a professional setting. In that setting, it doesn't even register unless it's obviously patronizing. Then you'll get the look that let's you know it better never cross your lips again.
I try not to do it here, e.g. I'm so sorry hon. To me it's a term of endearment, but I also wonder how regional of a thing that is.
Ditto
ETA: we also grew up in the same area. That could be why it doesn't bother us.
I would bristle but it would be completely out of the norm where I live. I cannot think of a single instance where I would find it appropriate outside of a nurse comforting me in a hospital bed. Even then, it would be weird.