Other Thoughts:
I had one day in the Seattle-Tacoma area and used this website to narrow down two courses to play. I chose SeaTac and Lakewood King County (Lakewood KC) because there wasn't a course nearby that was obviously much better than these two, and they are less than 3 miles apart.
If you're looking for privacy, a wooded experience, or a disc golf challenge, show up with what you need, including the google course map from this website, and get ready to work hard for par at SeaTac.
If you're looking to show up with only a pair of shoes and buy discs, snacks, drinks, a bag, and have a local give you some advice and a paper map, then get ready for a thoughtful course with decent variety in a typical city-park setting at Lakewood KC. This is also a good course to rack up the birdies.
SeaTac was hard to only play once. I wanted to play it again and knock some strokes off my score. Lakewood KC isn't that complicated, and I don't know that I'd do any better by trying again - it's basically all right there to figure out on the first go around.
Both courses are struggling a bit with upkeep. Lakewood KC seems to be struggling to hold onto 18 solid holes as they have other shareholders in the park impose their interests on them. SeaTac is just due for some new and better signage and more course wear.
SeaTac was relatively easy to navigate thanks to my smart phone and the Google course map available through this website (much better than the regular map). Without it, I think I'd still be turning circles in those woods. I still had to basket search some, because it is a forest. The landing jumbo jets keep you oriented though.
If you can't throw as you intend, you'll probably spend too much time at SeaTac in prickly bushes searching for your disc. My stroke difference on the two courses was about a dozen, and I can see from this website that it's not uncommon to need 20 or 30 more throws to play SeaTac compared to Lakewood KC.
Really, though, what I recommend is playing Lakewood KC first, fill up with all the things you need, start your day feeling good about your play, and then take on the SeaTac challenge.