Pros:
Beauty: First and foremost, Rock Creek Park is an incredibly beautiful rocky gorge cut out of steep rock walls by Rock Creek. We played in spring before most of the trees filled in which allowed for expansive views of the rock bluffs, many waterfalls, and the powerful springtime Rock Creek. From start to finish, the course captures a lot of the more interesting components of the park including water shots, basket placement on steep rock terrain, and big elevation shots.
Variety: Variety comes in the form of frequent elevation changes, tight turns wrapping around the river or rock walls, and from fairways which are 100 percent air to tightly constricted. You'll need most of the shots in your bag here, with perhaps the exception of long-bombs with high speed drivers.
Challenging OB: OB comes in two forms here: First, from a paved walking path that splits the two sides of the course - on many of the holes, skipping across this path is a very real possibility for any poorly thrown shot. The second is the more natural creek hazard which lines the right side of many of the front nine. While on most holes, it is fairly easily avoidable, in spring time when we played, it was bumping right up within just a few feet of pin placements.
Other Thoughts:
You probably picked this up already but I highly, highly recommend this course for everyone but very new players. Perhaps locals to the mountain west get to see terrain like this on a more frequent basis, but this course blew my flatlander mind! I've never played through such a fun, rugged, rock strewn park.
Marmot/Squirrels: Another really unique feature of this course is the ABUNDANCE of whistlin' marmots that live on the rock walls lining the course. Walking around the first transition bend to the back section of holes, we saw ~15 of the guys scurry from the grass to their safe rock dens, whistling and chirping warning calls all the way. Why were they so afraid you ask? I'm guessing the live .22 caliber shell we found while playing the course might have something to do with it!