I commute RT BKK-BOS-BKK roughly every other month. I only connect in HKG if I'm in F on CX using a mileage redemption. Otherwise, I have no interest in a 16 hour flight in Y. I get to NRT, take a shower (JL club admission based on PLT status), relax a bit, then it's roughly six hours to BKK. If I'm going to be in Y, I do much better with the longest flight only being roughly 12 hours. The extra time on the TPAC does make a difference to my body, apparently. I also like getting to BKK hotel at midnight or a little after. Travel is finished; and I'm nearly always tired enough that I sleep through the night.