Most have seen the recent AS promotions and coupons for the new Masterpark Valet Garage at SEA which offers 50 AS mileage points. Drop off was a breeze and you can even check in to your flight using the ITM before you get on the shuttle. However, the return was terrible. It took so long to get picked up at 10 pm that I literally could have been to downtown Seattle by cab before I even got back to the parking garage (and it would have been cheaper too). Masterpark has several shuttles but you MUST take the one with the correct letter for your garage A, B, C, or G which may take a half an hour or more. Most importantly, the cost is excessive and they tack on a very large Port fee that they do not disclose until after you pick up the car despite their advertised rates. Two days cost mid $30 and that was their coupon special rate. Upon arriving at the garage the staff were very efficient for a reason. I could sense people were very surprised by their bills so the staff is able to quickly hustle sticker shocked customers into their waiting vehicles. Use them if you dare...but don't say I didn't warn you. Who wants to come home and ruin an expensive vacation because of a bad parking garage experience?