I don't live in Chicago but i've had some experience in food service. Expect to be tired when you get home and smell of food.
I made more as a cocktail waitress at an upscale bar than at a restaraunt. Think $200 versus $50. The drunker you get them the better they tip (but not always). The hours are long and there is a lot of bs being a waitress. You get crap from the customers, your manager, and the cook even if it wasn't your fault. I got a good workout running around though. You meet lots of different people. Overall I didn't like to be around food that much because it got disgusting after awhile. Cocktail waitressing I found more rewarding monetarily, but when some people get drunk they get annoying or lewd. I had a couple of people grab my butt and they got thrown out. The smoke got annoying until it was banned within the city limits here. Old people don't tip well and young people don't really either. Working off of tips can be really frustrating too, because you never know if they are going to leave a lousy tip after busting your ass. But in my opinion an upscale bar or lounge is better than a restaraunt all around.
