I've never had any issues, either with just myself or my kids. I went in as basically a comic book noob and they were nice and explained things to me. They gave me promo tickets for the first Guardians of the Galaxy once when I went in with the kids too.

There's no denying that type of store attracts a certain type. Comic Book Guy from the Simpsons wasn't randomly made up. I have seen them have to get on people about the bag policy, and a few heated conversations with a lot of "ackchyually"s flying around.