I've been to this show for the past three years. It's definitely one of the better conventions in the country. I would say it's easily the second best. However, having been to Comic Con in San Diego last week, there's a big dropoff from number 1 to number 2.
There's definitely a good number of dealers here. You can pick up just about anything here. Are you going to score current things at retail prices? Probably not. But as far as older items go, you'll probably wind up paying fair market prices. The key though is to be a smart shopper. Know what things should cost and haggle for the best deal you can. It's pretty much a microcosm of dealers. Some are going to have good prices, and others won't.
As for exhibitors? Hasbro did not attend this show last year, and it seems that they're only doing Comic Con now. But you can find some Star Wars licensees like Gentle Giant, Official Pix and Dark Horse at this show.
As for the promoters? They do a decent enough job. But the cattle pens that they herd you into each morning in order to get on the floor at opening are borderline degrading. Not sure what the ticket price is this year. Typically I've attended all 3 or 4 days. But I'm not attending this year. It's a long drive for me and there's not much incentive for me to go. I did attend the Wizard show in Boston last fall. That one was a disaster! Poor turnout, poor facilities, and not enough vendors. I also attend their Philly show annually. That has actually turned into one of the best shows on the East Coast. I don't know enough to say about either their Texas or Los Angeles shows. Overall I think Wizard is putting together some good shows, so if you're inclined you might want to check out the Chicago show.