I belong to a guild and have participated in two small groups over the years. The guild is okay, but personalities can sometimes cause problems. Right now the leadership has improved and the gals who want to dictate stuff are not as active, so it has been better. As most groups we have a huge core of gals who don't do their share and a couple who are very pushy.
I have also belonged to two small groups, which initially were wonderful. The first was great until one of the founders invited a friend without asking. That gal caused so much strife that people started dropping out or rarely coming. It has since folded. The second is at the LQS and is okay. It is fun, but everyone is so busy that they don't make it a priority, so it's hard to plan a workshop or whatever.