I'm a member of CHAOS, and I live in Logan Square. The great thing about CHAOS for me is that a majority of the equipment you need for going all grain (mill, burners, pots, MLTs) is available for use at the club. I do all of my brewing, fermenting, kegging, and bottling at the club's brewhouse, which is great given that I have limited space at home. The downside obviously is that you have to pay monthly to keep brewing at the brewhouse. It's worth it for me, but is certainly not for everyone. I suggest you check out our Open House on June 15, or you can just drop by the brewhouse this weekend, as folks will be brewing both Saturday and Sunday.
Is there anything specific about CHAOS that you would like to know? I'm not sure what you mean by "beer aficionados." We're all beer enthusiasts, and the majority of our members are brewers as well. We have a few members who are more into the social aspects of the club, rather than brewing, but CHAOS is first and foremost a homebrew club.
Let me know if I can answer any questions about CHAOS.