Experts of any kind are notorious for going out of town the week before your deadline. Dear Malia, For several years I've been writing fiction in my spare time, but I've never submitted anything. Now I'm finally working on a novel that I hope to have published. Now, on to your questions. Having said that, I'll try to be reasonably objective on the subject.
Critique groups serve a couple of purposes.
They allow writers to get together with other writers, and they provide an opportunity for immediate feedback about your work. This is good. But you have to remember, the feedback itself is only as good as the other writers in the group. This is where the usefulness of critique groups can get iffy. Everyone brings in something he's working on for the group to read, or, perhaps, the writer is expected to read from his work.