Seatac and Lakewood are my two home courses! They are about three miles apart. Conditions at Seatac right now are about the worst they get. Check out this link from a couple of days ago: http://www.odsa.com/forum/viewtopic.php?t=8987
I played Seatac by myself a week ago and only lost two discs. I hardly ever lose discs! The grass is chest high in some places.
I'm not really trying to discourage you from playing Seatac just be prepared to spend some time looking for discs and the possibility of losing a disc or two.
Year around I usually play Seatac 2or 3 times a week but not in June or July.
Those months find me at Lakewood. A well maintained county park. If you decide on Lakewood just stay on I-518 straight into Burien. Turn right on Fourth Av SW. Go about two miles to S 108 St. and turn left. Now go about 200 yards to the first left into the parking lot. If you see a white VW golf/rabbit then that will be our local disc seller (Brian) who will help you replace your lost discs from Seatac!