I've been to critique groups, and I didn't feel like that
particular group gave me what I needed. I wasn't gunning for publication, I simply wanted to write and to see where that took me, I had a passion for writing. For a critique group it is important that you feel 'safe' enough to share and open enough to hear criticism wothout being defensive.
I have also been to 'support only' groups where the leader assigns an exercise or a prompt to do in the meeting and we all take turns reading what we have. Usually what we write in class is just very raw material and there is NO criticism allowed for that (unless asked for) There is an assignment given to complete between the next meetings which can be a bit more polished (not perfect) and the beginning of group time is the reading of our assigned writings. It really is a good way to get the creative juices flowing and to have an avenue to share our work (which is important)
There are many other ways to structure a group. I was a part of one that did floating houses for meeting space and the hostess would pick the in class exercise, that was fun

I was also part of one held in a community center with the same leader each time (I miss that woman *sniff*)
I'd love to hear any ideas, I am looking to start one very soon.