Pros:
Great general variety for a 12 hole course on a relatively simple piece of land, Ewing simply has a very intelligent layout.
Variety of distance from ~175 to 400+
Variety in elevation, as well as left to tight shots.
Variety in tight forested holes and wide open bombing holes.
Course is kept up well, nice tee pads, baskets, and benches, signs, the little things.
Multiple placements also add variety.
Cons:
Course can get a little unruly, long grass, and in the winter it gets very tough to play with all the sogginess and mud.
On certain holes if youy stray the course you can quite easily lose a disc.
Other Thoughts:
Ewing is a very fun course, the fact that it only has 12 holes can be remidied by playing Hoover down the street and possibly Champoeg if your making it a trip from the Portland area, definitely an underplayed course, it often gets overshadowed in the Portland metro area by other more well known courses. Even if you only get to play it once, the variety of shots makes it worth it.