The 18-hour travelling time between EDI and SIN can be productive, too, as long as the WiFi is decent. And coming into Edinburgh, you can arrive around 6 am, have a quick shower and breakfast, and be at the studio around 8 or 9 am. I would rate this experience a 9 out of 10. I'm taking one point off for the security theatre of modern air travel. However, I would say that Changi Airport deals with this much better than other airports.