Chicago Test Center - Pearson - 200 W. Adams

Took my 1st GMAT at the Chicago Pearson location at 200 W. Adams - got a 730.

Test center was very easy to find and conveniently located in the Loop. Staff was EXTREMELY nice and helpful throughout the entire appointment. They made me feel comfortable, especially my proctor Donnie, who gave me a little pep talk right before I went in and cracked a few jokes. Really helped calm my nerves. They also did everything they could to help me do my best. For example, they were very observant when my 8 min breaks started, so I didn't have to wait at all to get checked out. Each time I checked out, they reminded me of the current time and how much time I had for break.
Also, they automatically switched out my test booklet during each break and gave me extra markers.

Your personal locker is located right in the reception lobby, and the test room was just a few steps from the reception desk. Check in took about 10 minutes, and I was able to start my test 1/2 hour before my appointment time. The bathrooms are just outside of the reception area, and although you need a key to get in, they have plenty of keys available to sign out.

The room was a tad warm, but they had a few floor fans on and was able to adjust since I dressed in layers. Room was very quiet.

I can't speak for Parking options since I walked. But its located in the Loop, so expect to pay steeply for parking!