Pros:
Oak Park is a good one for sure. It's fairly flat, but there is some contour on several holes, especially near the end. Parts of the course are kind of heavily wooded, but usually there is a nice line with plenty of airspace. Quite a bit of OB, creeks ponds and a river, as well as a some mandos push up the difficulty by a degree. Some long par 3's and a couple of par 4's give you a chance to test the arm.
Two tees for each hole. The tees are concrete and they have good signs. The baskets are all in nice condition. Pin placements are usually in a spot that is protected by trees or on a slope to add some thought to how you make the approach.
My favorite holes are 17 and 18. They play along the ridge of the levee, and have the most elevation change. 17 is near 500 feet from the long tee, making for a hard par 3. The tee is atop the ridge, with a reedy creek to the right and a couple of trees on the left. The pin is at the bottom of the ridge on the left side, and the basket is raised on a tall pin. Dial in on that approach. 18 also tees on top of the levee, but there is a heavy patch of rough blocking the right side. The pin is in a low spot as the ridge comes closer to street level, and is totally surrounded by trees and rocks. It's a tough drive to keep out of the trees until near the end, when you need to enter at the right place. Another tricky par 3.
Cons:
The course layout is kind of choppy, crossing the road multiple times. There is a long walk after a couple of holes, and places where you might skip a hole if you're not familiar with the sequence. Have a good look at the map and grab a screenshot to take along the first time through.
Walking trails will have pedestrians of all ages walking near the fairways on multiple holes.
Other Thoughts:
Oak Park is a great park style course that has some tough holes. Its a pretty area to walk around as well.
It's par 56 from either set of tees. I couldn't bank the number of birdies I needed to offset my bad holes. The score was 62, with 2 birds, 2 bogies and 3 double bogies.
I had played Oak before, but it was some time ago. I am glad I got to play it again. Would definitely recommend.