There's yet another last few mile transit option in testing too, called "Ride 2" [1], free with bus transfer. There's 2 zones in West Seattle, one on the east side. Free transfer if you bus ride. It's perfect for those places that have lots of buses at a central area but not enough feeders, not enough parking and ride space. King county is trying really hard to make it work on transit and they are doing a great job in my opinion.
1. https://kingcounty.gov/depts/transportation/metro/programs-p...