I used the HAL transfer coming off Eurodam in June 8. My AA flight was 12:03 pm My debark time was 7:45, was actually called around 7:30. I walked straight thru customs and out to the bus.
The drop off at SeaTac is a long walk thru the parking garage and up the elevator and across the sky bridge to checkin.
The wait for security was bad-at least 30 minutes winding thru the terminal. TSA precheck was also long.
Make sure to take advantage of the free Port Valet service if your airline participates. You only pay airline baggage fee.