My best experience was hanging around in r/conlangs Small Discussions, helping out the newbies and being helped by more experienced users. I genuinely cared about that place, and I felt that the mods were actually trying to create a good community, not to enlarge their e-peens.

My worst is probably when disagreeing with a certain mod, who decided to distort what I said into the complete opposite, just to ban me. (I was being surprisingly polite so he couldn't ban me out of rudeness.)