One of the reasons I felt so lucky when the MiG Writers' group let me join: I never had to go through the above scenario. :-)
To those still looking for a critique group: make sure you find a group in which members are at the same or (preferably) higher level of writing experience. If you find yourself feeling as if you're not getting as much from the group as you're giving, then it's time to move on.
For those who are wondering, I found out about the MiG Writers when they posted on the SCBWI message boards saying they were looking for one more member. Here's the link to the Critique Groups forum, but you need to be an SCWI member to access it.
Before you join a critique group, try to find out as much as you can about the group and its members. The more experienced groups usually will do the same, asking questions to make sure you're the right fit within the group.
Some questions to ask about the group:
How old is the group? More experienced groups have had time to settle into a rhythm and system that works for everyone.
How experienced are its members? How much writing experience? How much publication experience, if any?
What types of writing are acceptable for critique? If at all possible, join a group that focuses on your writing interest. If it's a group that critiques multiple age groups and genres, then be prepared to do a wide range of critiquing in genres you may not be familiar with.
What are the rules for critiquing? How often are members expected to submit material for critiques (and how many words/pages)? How often are you required to critique? What if you need to take some time off (e.g. vacation or other personal commitments)?
Thank you, MiG Writers! :-)