Pros:
This is a small park course that is very well kept by the city of Longmont. For such a small city course, Clark Centennial requires a fair amount of shot variety. Holes 1-4 and 6 all have a creek which comes into play which is very small, but placed well enough that it is fairly hard to avoid without accuracy. There are a fair amount of trees, and holes 5,6, and 9 I would consider challenging in the sense of trees/obstacles blocking the basket.
Cons:
Course is a fairly crowded park with many foot paths crossing through. There are often little children running around the park, unaware of the disc golf course. Between holes 1 and 2 (and again on 3 and 4) there is a fairly large fenced in pond which players must walk around in order to reach the next hole. To me this is a large inconvenience. It is pretty much a large obstacle which discers must walk around but cannot play around or enter. Course is very small and is played very quickly (unless you are held up by non-discing park-goers).
Other Thoughts:
Clark Centennial is a well manicured park and a short, fairly non-challenging course. It is a great course to get out there, throw the disc, try out some shots, and avoid trees/water, but it is not very challenging and does not have a very creative or fun layout.