Being the trombonist I am, I went and joined the Trombone Forum. MAAAAN, lemee tell you, those guys are pretty dry.
I've been on forums where the people are upfront and tell you how things are....I've been part of forums where people sorta give you that cheesy awkward smile and a gold star and aren't readily able to admit that stuff isn't that gray. I've been on forums made entirely of trolls who can only put your best work down.
But never have I been on a forum where everything feels SO fact based and I actually feel like a MEGA_NOOB.