If you were going to go with Chicago, I'd recommend early to mid May. Before May, you'll get the spring breakers (both teachers and students) doing vacations. By the very end of May and beginning of June, kids start getting out of school and college kids start flying home. The first two weekends in May would be ideal... good weather, temperatures in the low 70's, and loads would be much better.
The only downside would be the lake temperature, since it will be down in the 60's... no beach time then. I'm not sure, but I think the beaches open on Memorial Day anyways.
Per room, I think you'll find a rate of about $100-$150 a night downtown at most places. Some higher-end hotels are more expensive. With four people per room, hotel at $150 per night x 3 nights / 4 people = $112.50 per person for the weekend. If we could get cheaper rooms, even better. Trains from each airport like I said are not very expensive. Plus, we can get from downtown to the upscale and fun Wrigleyville to start at Addison (Wrigley Field) to walk down Clark St. and bar hop. It is insane how many bars and clubs are on that street. Heck, maybe one of the days we could take in a Sox or Cubs game.
Here is a map of the train system we have in Chicago:
There is even a train to the Gary-Chicago Airport (South Shore Line) that goes between South Bend and Chicago, so if we can arrange a tour of Boeing's Corporate hangar that would be ideal. The train station is a mile and a half south of Gary Airport, so that is something we'd need to consider.
Like I said earlier too, there are three major airlines and two major airports here that we could try and arrange tours with.
Don't think I'm trying to sell Chicago because I live here. I mean, that is part of the reason, because I know a lot about this city, but I think it would be ideal for what is trying to be accomplished with NJC. We don't have the museums like DC does with the Smithsonian and the Udvar-Hazy Center, but I'm not sure if that is what we'd want for a networking event. In the past we've always tried to do something that exposes the group to an aspect of professional aviation, like the sim rides, tower tour, ramp tour, etc. Maybe we could even arrange a guest speaker from one (or all) of the airlines here?
Here are some websites with more information:
www.flychicago.com
www.transitchicago.com
http://egov.cityofchicago.org/city/....do?entityName=Tourism&entityNameEnumValue=41
http://egov.cityofchicago.org/city/webportal/home.do
Oh, and yes, Daley sucks for Meigs. But you'd be surprised what he's done for the rest of the city... it is very clean, accessible, and safe.