From a client standpoint, a “Chicago” visit is really a tale of two cities. There is “the City,” Chicago itself, with its world class hotels, dining, cool coffee shops, and shopping. Staying in River North, the Mag Mile, and the Gold Coast are probably your best bet for an enjoyable stay and maximizing client opportunities.  The Loop, the financial district, is not really a good idea.
The other side of the coin is “the suburbs.” The two best options here are Oakbrook and Schaumburg. Plenty of hotel, restaurant, and shopping options. More chain type experiences available, but  nicer end chain options are available…you just won’t find 5 star accommodations or Michelin star restaurants. But, again, many nice higher end chain options, particularly steakhouses. The shopping? Major malls located in each suburb that can keep you very busy.
What I guess you need to know is that “City guys” don’t go to the suburbs, and “suburban guys” don’t go to the City. Parking and traffic are the two major impediments.  I guess you could say that the O’Hare airport area is a compromise, but again, traffic can be a challenge.  I’m not sure why our area does not get as many touring companions as other major cities, but my guess it has something to do with the unwillingness of potential clients to commit in advance, in these days of deposit only companions, when things like battling traffic can be overwhelming . But that’s just speculation