Im looking to find a meet & greet in teh chicago area, perferably south or west suburbs.   How do these differ from a Eyes WIde Shut gathering?

A typical M&G is an event any known hobbyist with references can attend.  EWS events are private events that are a completely different story.

Note that if you ever attend an EWS event, getting invited to an open M&G won't be an issue.  The reverse doesn't apply, though...