If your wife wants to check out Chicago, you may be better off getting a hotel closer to the city.
Sound is usually better on Saturday and Sunday, but least crowds on Friday.
Making a list of gear you want to see floor-by-floor is a good idea.
Also be sure to bring music that you are familiar with and which nicely highlights aspects of music that are most important to you. I bring both CDs and vinyl. You won't always be able to put this music on, but often there is that option.
I'm sure that ACers will also be getting together for lunch/dinner/drinks over the course of the three days. I had a great time meeting so many AC folks last year. If this appeals to you, make sure you factor that in when coordinating with your wife.
And be aware that it is often possible to get great deals on gear demo'd at the show if you are ready to pull the trigger.