Korean Air Skypass - Advice for First-Timer on KAL Business Class

Am flying Seattle-Seoul-SGN Oct. 28 in Business Class. Holding seat 7H on the first leg and 8J on second. If anyone has made this trip before, can you offer any advice on choice of seats, meals, lounges? Probably will not have time to use lounge in ICN due to short connection time. Wondering if there are lounge facilities at SEA or SGN. Any advice for transportation to Saigon Renaissance Hotel in District 1 from airport with arrival at 10:50 PM? I've heard stories about rampant taxi rip-offs in Ho Chi Minh City. Any "first-timers" advice relative to KAL or navigating around the city will be appreciated. I know this is a tall order but will appreciate anything salient. I'm somewhat apprehensive about touring alone in Saigon. Thank you.^

I believe that the route uses the 77W with the new lie flat seats 5 days out of 7 (as part of a JFK-ICN-SGN route). I believe that the lounge in SGN is a Airport owned lounge that is not great. Do not have much other info as Trip Reports on KE not that common.