Pros:
The Dayton area has had several new courses installed in the last few years, and Beavercreek's Karohl Park is one of them. Over the last 18 months, it's transitioned from a scrubby, soggy deuce-or-die track to one of the 2-3 best in greater Dayton. The county parks department does frequent maintenance, and the greens & fairways are cut regularly.
There's a great mix of hole types here, with the front 9 being more open and the back 9 being more heavily wooded. You'll need both a forehand and a backhand to score well here, particularly in the wooded section. Highlights include: Hole 4, with its late window near the basket on the right; Hole 11 in the long position, with an open tee shot to a wooded approach; and Hole 12, a 400' tightly wooded beast (one of the best holes in the Dayton area).
All teepads are concrete, and there are short and long tees on 7 holes to provide appropriate challenge for different skill levels. Multiple pin placements are available on most holes, and baskets are rotated frequently.
Brand new Veteran baskets (one of my favorites) were installed in June 2019 to replace the controversial Predator Great Whites. There's a practice basket available by the gravel parking lot, and it's often used as a 19th hole during events. A port-a-john is by the parking lot as well.
You're unlikely to lose a disc here unless you're playing it in the summer (see Cons).
Cons:
This course is really flat, and that presents a couple of downsides. First, there's not much in the way of elevation change to liven up some of the more open holes. More importantly, it doesn't drain all that well and gets squishy when it rains. It's especially bad around the walk from hole 2 to hole 3, though some of this was a result of neighbors emptying their sump pumps into the park. They were caught and have stopped doing this, and it appears to have alleviated the problem somewhat. The parks department installed wooden bridges over the worst of it.
In the summer the rough gets really thick here, and if you shank a tee shot it can be a pain to find your disc. Worse, there are lots of deer at this park, and that means lots of ticks. Make sure to bring bug repellant.
A tall chain link fence down the left side of hole 11 and right on 18 defines the park's property line. Do not jump this fence to retrieve lost discs. One of the locals works with the property owner to get them returned to their owners.
Other Thoughts:
Every hole except 6-9 has either had additional pin placements or long tees added, and as a result most of the tee signs are out of date. Until the new signs are installed you should check the distances listed here on DGCR. Those are correct.
With all the work that's gone into this course recently, reviews from before late 2020 don't remotely reflect its current state. If you haven't played it recently, definitely give it another try. It's better than you remember.