Pros:
Katherine Legge Memorial Park is a beautiful and well-tended setting to host a disc golf course. The rolling hills throughout the course provide some great variety in terms of elevation to contest with, especially on the front nine. The first half of the course includes a shallow creek as well, and there are several downhill shots made significantly more hair-raising owing to the need to consider this hazard. At the same time, the water is shallow enough to easily retrieve your disc, which is nice (or at least it was during my visit).
Trees dot the landscape throughout, and while the course is far from technical there are certainly obstacles to consider on most holes, be they barriers to bend around or ceilings to avoid. The course plays plenty open all the same, lending a free-wheeling sense in which a variety of lines can be thrown on most holes. There are some opportunities to really let loose regardless of how studly your max D is. The result is a fun and casual course that plays more quickly than its overall length may first suggest.
Navigation is easy, parking is plentiful, tees are well-signed.
Cons:
The light tree cover and straightforward hole layouts ultimately made this a boring course for me. You can throw hyzers on every hole, especially if you're even passably FH/BH versatile, and there's nothing to punish landing a bit or often even a lot wide of your mark save for the creek at a few points. You're never forced to think or adapt your game, and there is no line-shaping beyond the very basic. As such I found myself coasting by the end of my round.
DGCR lists three sets of tees but only one, the long, was visible by my assessment. This course had only a single layout from what I could see although it's easy enough to be welcoming to players at all levels.
For a course that encouraged pushing for distance I found the concrete tees to be too short at times.
Player traffic seems higher here than many other Chicago-area courses I've visited.
Other Thoughts:
Katherine Legge makes for a casual round that plays quickly for 18 holes at almost 6000 total feet. It's a solid option to stop at as part of a larger day trip, but not a course I'll likely return to again as a visitor to the area. If you're looking for a light round then I'd recommend it; if you want something technical, try the excellent nearby Central Park.