I will like to know if clients prefer incalls or outcalls?
Incalls in Downtown Chicago or Ohare... which is better?

I say incall is better

I get the most business with a downtown incall, especially on weekdays during lunchtime, but, during the evening as well especially if there's good parking where you are. O'Hare incalls have typically left me kinda bored during the day but more bookings at night. It all depends on what you prefer.  

Downtown and Ohare are about the same, as far as best place. Whenever possible, try to hit both. And I think having an incall but also doing out calls is optimal. I prefer incalls, myself, but will do outcalls if I am comfortable with the gentlemen.

The reason is I have everything you would possibly need plus I provide beverages/snacks and a very large suite.

Incall in an upscale hotel with bar and restaurant.  There are ton of reasons why I would be in a bar or restaurant but no reason to be in a $79 motel with doors that open to the parking lot.