Groups vary. Some are made up of good people with compatible outlooks and compatible and adequate funding abilities. Most are hanging together "ok". And quite a few are falling apart, with some members taking the micky but nobody dares to do anything about it because the setup would fall apart and they would not have any flying.
And be assured that if you are buying into a group, the existing members are not going to advertise existing issues, either personality/behaviour issues or problems with the plane.
100% ownership is great if you can afford it.