Pros:
For a casual park 9 holer, Old Economy has a nice mix of distances, with some short par 3s, three holes over 300', and an additional two holes over 400'. Getting to stretch out and throw some distance drivers was a nice surprise, and there are opportunities to reach for a range of other discs off the tee, too.
There are a variety of hole types, with mixed levels of woodedness and elevation, although the tendency is towards more open shots. Shot variety is decent, and even the multiple straight holes come in different flavors. 4 is an enjoyably technical tunnel shot that makes for a tough three, and 5 challenges your placement nicely with a combination of sloping terrain, OB, and the tree line. The rolling hills throughout the course spice up some otherwise-conventional shots, and there are a few enjoyably-scary hillside pin placements.
Parking is plentiful. The course is easy to find within the park, and navigation is straightforward. Grooming seems regularly upkept. A nice, sizable, and clean portapotty is on site.
Cons:
Old Economy Park is a pretty basic course, with several very open holes and an overall lack of line shaping. 4 is pretty much the only technical hole. There's a bombs away feel to several holes due to the lack of obstacles, and a few others that come close to that sense as long as you manage to steer within a very generous lane. The replay factor is pretty nil if you don't live in the neighborhood, IMHO. There are just too many other great courses nearby.
The tees are really terrible: ruts in the ground filled with wood chips that make for poor footing, and dug low enough and short enough to risk turning an ankle or the like if you step long (very possible). I didn't use them.
Old Economy has the worst in and out I've ever seen. The holes play progressively away from hole 1, leaving you a walk back that could rival the duration of your round. I'm not one to complain about such things generally, but here it was really poor. You'll regret this design choice on a hot summer day.
Other Thoughts:
Old Economy Park's disc golf course has some fun distance, but otherwise not much to really draw you back there. It makes for a nice quick stop if you're visiting Knob Hill or Linbrook, but should be pretty low on the priority list when visiting the area.