Pros:
EDIT: The course is now 18 holes. Holes 10-13 are pretty well defined. Holes 14-18 have a marked tee area and baskets, but are still under construction and rough.
Unger Park DGC is now a nice Intermediate/Rec 18-hole course. Holes 1-5 and 10-18 are cut into the woods and Holes 6-9 are out in the open. The wooded holes are 200'-250'ish shots and the open shots stretch out to 300'+. Hole #7 uses a mando to stretch out over 600' and has a protected pin placement, so it is a legit rec par 4. The open holes have a few trees (except #9, which is a wide open grip and rip shot to get you back to the parking lot) that make them at least interesting. Hole #1 had a pretty tight gap you have to hit to birdie the hole, but otherwise the wooded holes have generous throwing lanes so you can avoid serious trouble. The thick punishing underbrush that was a feature of the original 18-hole layout has been cleaned up quite a bit. The tees are turf with benches at most. There are posts with no tee signs, the distance is written on most of the posts. There are good directional markers and the course flowed well so it was easy to navigate. The course has nice DISCatcher baskets that are easy to spot other than holes #2 and #7. The course had been fairly well mowed when I have visited. All-in-all, it's a pretty nice rec course.
Cons:
The park is essentially a retention area for the Meramec River. As such, it is flooded a lot and swampy most of the time. Most of the holes are set up in a part of the park that doesn't flood a lot, but hole #8 is going to go underwater at some point. It is set up pretty close to the retention pond.
Maintenance was an issue in this park in the past. Grass was left to grow and the underbrush was untamed. Right now it looks kept up very well, but that will need to be watched. There is some poison ivy out there, so be aware.
Holes 6/7/9 run together. Hole #7 has a mando tree to keep you from throwing at the fairway for hole #6, but that mando makes you more likely to flip your tee shot on #7 over into #9's fairway. You have to watch what players on other holes are doing when you play these three holes.
Other Thoughts:
History: Unger Park disc golf course opened in January 2009 to great fanfare as an 18-hole championship course that aggressively snaked up and around a huge retention pond. The course had a monstrous water carry on Hole #11 followed by three shots up the side of the pond. The aggressive use of water as a hazard had the local DG community buzzing.
Then, the course flooded. And it flooded again. And again. The retention pond has no outlet. Once it fills up, you have to wait for evaporation to get the water out. By the summer of 2010, the course had been under water almost as much as it had been playable. When it had been playable, the maintenance and upkeep by the parks department left a lot to be desired. Three of the baskets that were not under water had been stolen while the course was unplayable. The experiment was not working out, so the championship 18 was redesigned into a recreational niner. That course was not well received and by the end of 2011, all the baskets were removed from the park.
The local disc golf club still had permission to use the land, they were just choosing not to. In 2017 the club decided to give Unger Park another try, so a new course was established.
One of the odd things that happened when Unger went from 18 holes to 9 was that it seemed like holes 1-4, 7-10 and a shortened 18 could have stood as 8 shots with just a little tweaking to make nine holes. Instead of doing that, 9 entirely new holes were cut in that were pretty short and pretty boring. A lot of work was done to clear out shots that were not as good as shots that were out there, when the easier option of reusing existing holes would have made a better course.
This new design I think reuses some of the original holes from the 18-hole course. It's been so long since I've played the original 18 at Unger that this could be totally wrong, but I think #1 is basically the same shot as it was on the 18-hole course. I think it's a shorter tee to the old placement. Hole #2 I don't remember so it may be different. Hole #3 is the same. Holes #4/#5 are I think old holes #8/#9 on the 18-hole layout. Holes 6-9 use some of the elements of the old course, but the shots are new. Hole #6 uses a new tee to shoot up to where #18's pin was, Hole #7 uses a new tee to shoot to where #10's pin was and #8 is a baby version of the monster hole #11 that curved up around the bottom of the pond. It just plays along the pond now with no water carry. None of the shots from the 2010 9-hole layout were reused in this design to the best of my recollection.
With the addition of holes 10-18 the course is again 18 holes. At this point the new holes are pretty rough but are in keeping with the wooded holes on the front nine.