Pros:
The potential for a really great casual course is definitely here. Oregon Park has undergone a lot of changes in a short time, moving from 9 holes to 18 in early 2009, and as of November 2010 a second full 18 hole course is on the adjoining park property.
The space and layout of the original 18 holes are a good mix of open holes (1-6,10-12) and wooded more technical holes along the creek (13-18). The course is sized well for players just beginning to play disc golf, as almost all the holes are under or around 300 ft. and provide simple/straightforward approaches. Few holes finish right meaning most right hand back hand throwers shouldn't need anything other than a basic throw.
The course is really open and most of the holes provide easy visibility to the rest of the course. The park as a whole is really well maintained and the start of the disc golf course and parking is (sorta) easy to find.
Cons:
As good as this course could be it's got a lot of little things wrong with it. First off, finding the holes, even with a map on your first time out can be difficult, and finding both white and blue tees on every hole is a challenge (I still don't know where about half of them are even with a map). The baskets really don't help as many don't have the hole number on them and they seem to be mix of DGA and Discraft catchers with nothing bright to help pick them out at a distance.
While the layout itself makes good use of the available space, it makes for some awkward holes and (mostly) natural tee placement that can be problematic. After a good rain many of the tees are dugout muddy messes, and the back 9 holes along the creek can get really slippery and muddy making finding a good foothold a hassle. Of course these problems aren't unusual, but the course has a good deal of erosion and wear probably due just to the amount of traffic it gets.
Unfortunately the course can get really crowded quickly, and not all of the players I've encountered are polite disc golfers. Despite how easily visible all the baskets are from the pins other players don't always wait for before throwing, and with such a crowded layout it's easy to hit someone on the same hole, or even one of the other holes since some holes (3,4,10,11,13,14) overlap a little.
Signage is almost entirely non-existent, and some that's left over from when it was a 9 hole course is downright confusing.
Other Thoughts:
This is my home course, and though I've only been playing since Summer 2010, I'm on the course weekly. I really enjoy the course but it's quite a ways from the best course it could be.
Improvements as simple as signage, a definite layout (holes occasionally change for "tournaments" and some tees are just impractical) and better tees (concrete, or even simple gravel) would all go towards making Oregon Park a really good disc golf course.
Now with a second course on the property I'd like to see the original course become an easy to navigate, concise course, that's great for beginners.
Since Oregon park is the only disc golf course in Cobb county, and therefore it gets a lot of players everyday, it really should be at least a well maintained, thought out course.