Frapos, we got very lucky. No Online checkin at SIN but the NICEST transfer desk staff at 3am, when they opened! One security guy, John Palmer, was extremely helpful. Used to work for TSA and even knew airports like CVG. He did the docs routine and waited with us for the DL agent. She was a delight, too. Changi is the way to go! Our Garuda flight was Skyteam so it was the same terminal. Great experience.