The OP didn’t actually mention general-interest boards specifically, although others have. Mine is a special-interest board, fouintainpennetwork (dot) com. It’s the only other board I am on. The software is different, and they are very polite (the software will substitute nicer words if you type in recognizably bad words), usually intentionally. There are one or two posters who have mastered the art of politely making you feel like a dumbass, but most are not like that. And the level of available expertise on the subject matter (pens, ink, paper) is astounding to me.
There is no outlet there to scream at people who drive you crazy, but I find I can get along without that. There is some blurring of roles, as when moderators post about a thread content without saying whether they are doing so as moderators or as posters. I sent a PM to one of these who didn’t seem very bothered about it, but who said he would try to make that more clear in the future. Also, at least one moderator is in the business of pen repair, and his signature in every post is a big old ad for his business. Everyone seems OK with that sort of thing, perhaps because it is not a huge community and lots of people know each other. Which can be somewhat intimidating for new posters who don’t know the ropes. When my toes got slightly stepped on in my first thread, I complained mildly and everyone instantly backed off.
One thing I like about the board is the relatively high percentage of posters from outside the US. Many of those, and almost all of the native English speakers, write with excellent grammar and spelling, which is very salutary for me.