Pros:
In this course, there the front 9 holes and the back 9 holes. These add to 18 total, by sharing certain baskets (and in this case, natural formations). This could cause periods of overlapping the same hole, just be patient and wait for others playing. The hazards on this course are the strong winds at this part of the island, and the highway/base entrance. If your disc goes over the fence, good luck getting it back easily! It's a nice flat area in the sun, very quiet and peaceful. All-in-all, a fun free activity!
Cons:
Going to Dexter's Alley, it's clear to see that once this course had a lot of time and effort put into it. Today, while still super fun, it's missing some of the grandeur necessary to make it a truly great course. The disc golf enthusiast that created the course has since moved from O'ahu and taken about four baskets necessary to make this complete. While this is a disappointment, it can easily be remedied by picking natural formations (like trees) to stand in for the missing baskets. It makes these holes less of a challenge, but one can still complete the course.
Other Thoughts:
Dexter's Alley is in JBPHH, right inside the main Hickam gate. It's in a residential so be respectful to the homes and yards surrounding the public space. Dexter's Alley is an alley/park, with plenty of parking. There is a road that runs through the course, but it's almost never used. On base, there is free parking almost everywhere, just pay attention to the signs. One big benefit of this course is it's free. It's also open anytime, so come at your leisure (obviously, it's better during daylight).