I used used a few in chicago
Marriott naperville and the lincolnshire resort are both cat 4 and nice properties. I liked naperville better, but the lounge at lincolnshire was better

Both have easy access to METRA. Shuttle will take you to train station, Bout an hour ride to union station in chicago. Lots of fun things to do. I recommend the shedd, msi, navy pier, and mag mile for tourist stuff and shopping. Its only 7 bucks for a weekend metra pass.