I was surprised and pleased at how easy it was to book my ATW flights. I spent maybe an hour on the phone with a very helpful rep. Expected most seats would already be booked for this late-June, early-July trip, and I was prepared to be extremely flexible. But in the end I needed to make only modest adjustments to my hoped-for itinerary (and those were only to line up the least-stressful flights). Heading from IAD to Amsterdam, Bangkok (via Vienna), Auckland (via Sidney), Honolulu, then Maui to IAD (via San Francisco). Honolulu was booked so they let me leave from Maui (I will arrange that flight separately), which I wanted to visit anyway. Was surprised to find out I had to mail my precious certificate to Michigan to get the paper tickets issued, but apparently that's how the plan works. Flying United to Amsterdam and from Hawaii, and also Austrian Air, Thai Air and Air New Zealand. Update: I just got the paper tickets in the mail and all seems in order. Took approximately 2 weeks from the time I made the reservations. All told, the process of redeeming the points for actual tickets was reasonable and straightforward, although it did take some time.

For international flights, I was told I couldn't book online or with an airport rep, but had to call United.