Pros:
Edit 5/14/15: Saw it noted that they've added holes to 27, so I looked for info on Disc Golf Scene, Columbus Flyers, Facebook, and found something onMid Ohio. Added that link and the updated map.
Original Review: The family of Gordon Holton should be proud: this course is a gem in a beautiful park with majestic trees, a gorgeous lake, and rolling terrain that all come into play throughout your experience. Almost every one of the (20) holes at this disc golf course in (Ohio's) Delaware State Park feels different from the others. From the down-slope opener with a guarded basket - 25 feet in front of a twenty foot drop to the water below, through the fade shot back to the optional 20th (also used as the practice basket), you'll throw power drives up a 400 foot gap between tree rows, tricky, right-turning blind shots with nasty rough if you cut it too tight, and woods-threaders ... and everything in between.
The use of elevation is wonderful, but not overly taxing: you have a few shots where you'll be able to see the treacherous woods - valley - creek beds - etc. that could wreck your score, while at the same time be tempted by the fact that you can choose multiple lines to get across the space between you and your goal (I'm thinking of holes 11 through 13 and 16 through 18 here). There are water carries from a couple of the long tees (7 & 14). There are long tee holes over 430 feet (9, 10 & 13), if that's your cup of tea. And there are even some pretty risk/ reward opportunities, if you can hit the perfect line (2, 8, 16, for instance).
The park has been tremendously well-maintained the times I've visited, and the course has nice concrete tees (14 holes also have long tees), newer signage that's very easy to spot, quality DGA baskets in good repair, benches and trash cans where needed, abundant parking (four lots adjoin sections of the course), park 'restrooms' (OK, outhouses), and a nice kiosk with map and 'happenings' by hole 1. Even though the course meanders over many, many acres of the park space, it plays through fairly smoothly and quickly because there aren't too many long treks between holes
Intermediate to Advanced disc golfers will do well to break 60 for the 20 holes, but the course has attractions for players below and above those skill levels. It's a very well-balanced, fun experience. Well worth the trip, with even more quality courses (The Players' course at Alum Creek, and of course, the Brett Hambrick Memorial) fairly close by if you traveling into the area. The state park obviously has camping, boating, and hiking options, and you're really close to the north side of Columbus and all of its attractions.
Cons:
The course can be pretty muddy in the spring, so come prepared for that. Though most of the paths to the next tees are intuitive and well worn in, you may need the map to find hole 4: it's out to the clearing at the dual ponds, and around the bend to the right. Then, I'm pretty sure they've done some extending of the pond left of the 7th fairway in between my two visits. It's unfortunate that they placed a park bench in line with the long tee shot. You will want to turn to your right after the 17th basket, and not head out by the parking lot looking for 18. There is the awkwardness of having a hole 'G' (for Gordon?) between 11 and 12, or if you skip it to play only 18, having the one long walk across the parking lot there. Finally, it's a little unusual to have the 'spare' 20th hole finish back to what arriving players will be warming up on as a practice basket.
Other Thoughts:
I've only played three rounds at Gordon Holton, but already have a wonderful memory I'd like to share. On the 260 foot hole 8, I parked a glidey River seven feet past the pin. Not unusual, except for the fact that I had just released the disc a hair early and inadvertently made that shot through the gap in the V-shaped tree on the left side of the fairway! There couldn't have been more than 2 or 3 inches on either side of the disc as it slid through the air between those trunks. Could never have made a shot like that had I called for it. (Can you tell I love this game?)