What is the most efficient way for a group of 10 (6 adults/4 kids) to transport from Pier 91 to SeaTac? Our schedule will be tight as we have an 11:10 Sunday am flight. Thinking it will save time, we plan to use Port Valet. Is there an advantage to register for Spot Saver if we have TSA Precheck, or are they basically the same? Recommendations for private transfer options appreciated.