Pros:
The best thing about this course is the variety of distances. Holes 3 and 12 use a midrange at most, while hole 9 is a full out drive and 11 takes two full shots even for an above average player. The rest are mostly fairway drives, with a couple of slightly uphill shots that might require a full throw depending on the player. This course can look pretty easy at first, but a bad shot can really put you behind. If you don't make it through the trees on 1, it's a tough save for par. Into the left woods on 8 or 9, and a drop might be the best option. Finally, the course does a great job of protecting the baskets with the few trees that are present. Holes 2, 3, 5 and 6 would be easy birdie chances if it weren't for the tough greens (5 is in the middle of about 10 trees).
Cons:
Quilchena is a very popular, multi-purpose park. You are constantly having to pay attention to the walkway for joggers and children, there are often soccer or softball games going on, and there is an off-lease dog park in the middle of the fairway for holes 10 and 11. If you're not comfortable asking people to look out, or confident in being able to control your tee shot, then you might be better off playing somewhere else.
Other Thoughts:
As a result of the public traffic, there usually aren't many disc golfers on the course, so it can be a good place to take someone who wants to learn. And since it is in a really nice park, take a picnic basket and a ball for a whole day with some friends.