Definitely a TR!!
Ps. Any special treatment at the hands of CBP upon your return to the US?
No not really, guess an Aussie (having already entered the US multiple times from SYD) doing this sort of thing is not really on their radar. There are some issues that come to mind though.
First is that it did not seem to matter whether you stay at the airport in the foreign leg and not pass passport control in the foreign country, they still write the country that the flight stopped at anyway, so I guess on their system it looks like you left the US and stayed at the foreign country, even when this was not your intention. This may have implications if I were to become a US resident one day, a few days trips to CA region may need some explanation.
Second issue is print something off the Qantas website so that you can show then what you are doing. The first run, I simply tried to explain what I was doing, no matter how I tried, the passport control guy just did not get it and to some extent became confused about the issue. Guess that in MIA, all these guys do most of the day is deal with central and south American passports and visas and documents so they are a little drained at the best of times. The second run was a lot easier, I printed the SC page off the Qantas website and my actual account and what was needed to attain these levels. The second time that I went through passport control, it was far easier and to some extent the officer was interested in the concept and how it worked. In short, I don't think that these passport control officers are the sharpest tool in the shed.
Third, be careful what you eat, remember, these flights are long, I wouldn't eat any meat or fish in case you have a disagreement, I threw up all the way from BWI to MIA (some remnant of a super cell and tornado events in the Kentucky area threw the plane all over the place), and then had the pleasure of trying to recover with a 3 hour each way trip to a hot central American country with and then another flight after return to MIA all in the one day.
Fourth, although most of these flights are first class, the single aisle MD80 craft are really something that you can not relax in, they are old, seats have limited recline and there is no foot rest.
Finally, if you are sleeping in the airport, make yourself known the airport police that are on patrol, OTHERWISE, they will continually wake you through the night for proof of ID, eventually I found the solution was to have the boarding pass for the morning flight and place it where they can see it, a couple of times I noticed that they picked it up, checked it and then went on to hassle the next person for ID
