Pros:
In the mostly flat North Texas landcape, the elevation changes really set this course apart, especially since it's not out in the middle of nowhere. I've been playing for almost five years in DFW, and only recently found out about Turner Park. I was amazed at the amount of uphill and downhill holes.
Despite the numerous large shade trees, the course has an open feel to it. There is very little of the scrub brush that you find on the outskirts of the DFW area (as always, do keep an eye out for the occasional locust tree and its spines). Unless you go way off course, you won't spend any time hunting for your disc. There is a creek running through the park, but again, nothing from which you can't easily retrieve your plastic.
It's easy to see that a good amount of thought went into the design of the course. It's in a mixed use park, but the mandos and the layout help to avoid the non disc golfers.
All the tee pads are concrete and in great condition. Some feel a little short, but for the most part they're relative to the distance of the hole. Almost all tees have benches/picnic tables, trash cans, and shade, either on the box itself or very close by. Every tee has a sign, showing accurate hole info and a course map.
The baskets are in great shape, and on the longer holes, have a tall, bright flag on top to help locate the pin. (Another nice touch: at the alternate pin locations, a 2' - 3' piece of white PVC pipe is placed in the post hole. On the longer holes, this makes it very easy to tell what position the basket's in from the tee box.)
Cons:
There isn't much to not like about Turner Park. As others have said, the trash cans were overflowing, but then again, that was the ONLY place I saw any trash on the course.
This is not a course at which you should expect to get in a quick round. It's amost 7,000 feet in hole distance alone. Add to that the elevation and the often long walks between holes, and you will feel every bit of your round when finished. (I should note that I played on Memorial Day, and the temperature was creeping into the mid nineties by the time I finished. If you plan to play here any time between May and October, go early!)
Other Thoughts:
The layout rewards long and accurate shots of all kinds but, for the most part, you don't have to be huge off the tee. There are definitely some tight, difficult lines, but they feel natural and make good use of the landscape. You won't find any gimmicky or made-up holes here. You do have to be very good around the pins, though. Most of the baskets are situated either on a slope, or right at the edge of pretty severe drop-off. A 20 ft putt can easily become twice that coming back.
I just played here for the first time. It was hot, humid, and I posted a terrible score, and I can't wait to go back.