Pros:
Portland Park DGC hosts a nice and compact nine hole course in a passive park at the base of Signal Mountain in Chattanooga. Besides the course, I saw no more than green space around the area so chances are that disc golf has the park to itself, except maybe an occasional picnicker, etc. You'll be greeted by a parking lot with moderate parking for the course's size, an information kiosk, and an easy walk to hole one. From there the navigation is pretty easy to follow on this strait forward yet thoughtful layout.
Although there's only nine holes, there's a fairly good mix of hole types. Besides no long bomber holes, you'll have most of the other things you'd hope to find on a course. A couple of tight wooded shots, up/down shots, and even a big dogleg are here with the overlying theme being moderately open peppered with mature trees. There's plenty of signage, concrete pads, and other nice amenities here too. The newer baskets are in great shape and catch well.
Cons:
There's really nothing terribly bad at this course, remembering that it evidently wasn't intended to be a championship caliber course. My biggest complaint would have to be the main road. I'm always distracted by nearby roads with lots of traffic when playing. This course is no exception as you'll be facing it on several holes here. Secondly the park is small and as others have mentioned, it could get a little cramped if the course is full.
Other Thoughts:
Keep in mind that this is not an overly difficult/challenging course. I would imagine given the design and location that it wasn't designed to be. I'm thinking this is a good course for newer players or convenient practice for the advanced players. As others mentioned, being close to the main road helps give disc golf a little free advertisement and hopefully promote growth in an already thriving disc golf community.
If you're visiting the area and you have time, try to head up the mountain and hit "9 on top DGC" too. It's an even shorter little nine holer but it's a nice drive up the mountain and you can run through it in a matter of minutes. For me it was worth the trip to play both courses to add a couple more to the "played list".