Pros:
Deis Hill is a very well maintained course. The grass is always cut, the brush removed, and tees and baskets kept in great condition.
The scenery is fantastic, and the park as a whole is a really great place to spend a day. Forests, fields, lakes...Deis Hill has it all.
The course is long and open, so it also helps put your shots in perspective, and lets players experiment broadly with the flight patterns of their discs and various throwing techniques.
Cons:
Deis Hill is extremely long, but it lacks any real challenge. Most of the holes are fairly open and straight; those that do dogleg often do so in odd places and at inappropriate angles.
Unfortunately, Deis Hill's length makes it less desirable for both new players and veterans alike. New players will at first enjoy the open space to work with, but the distance quickly wears out the arm and becomes intimidating and daunting. Veterans will quickly grow bored of "grip it and rip it" shots at such frequency.
Other Thoughts:
Deis Hill has a lot of potential, and a lot of space to work with. They could easily have used the land to make two 18 hole courses that are more varied and challenging, but as it stands, it's nothing special. Especially considering the other courses nearby, like Arboretum and Lincoln, Deis Hill just isn't that great.