Pros:
Holes 3-7, 17 and 18 are wooded but very fair, presenting reasonable gaps and elevation changes. My favorite of the course are 6 and 18, two sub 600' par 4's that are about placement and not distance.
The rest of the holes are mostly wide open and longer, balancing a park style course with the more typical wooded Nashville course experience.
The design is quite thoughtful, making decent use of the space. While the wooded holes have gaps to hit, the open holes for the most part include elevation changes, OB paths and fences, and sometimes sloped greens.
The course distance and elevation changes make for a pretty active round so you can get some great exercise too (may be a con for some people).
While this is a multi use park, the course is in a section with nothing else. I've never seen a non disc golfing park goer on the course. That also means that there is almost no litter on the course which is another pretty rare thing for a course.
The maintenance and care for the course is top notch. The tee pads, tee signs, regularly mowed fairways, wood chipped greens and new baskets are all a pleasure to experience.
Cons:
A course using this big of a wide open space is bound to have some filler holes. The stretch of hole 8-11 is pretty forgettable. Other than an OB path between holes 9 and 10 there isn't really any danger or intrigue.
13 and 15 are a couple more fine but fairly unmemorable holes.
Lack of a bathroom or practice basket is an area for improvement.
Other Thoughts:
Regardless of whether or not you're looking for a wide open park style course, The Highlands is a completely different experience than Cedar Hill / Oggwood / White House/Seven Oaks.
It brings some of the openness of a Naval Hill or a Two Rivers but with a variety of pars and a great mix of wooded holes. Not every hole is great but it's still a lot of fun. It also has the only par 5 that I know of in the Nashville area and way more par 4's than any other course around. Definitely worth checking out.