If you chose to get blitzed in all the lounges on the way, you would have a serious ethics problem, but it would not be one of bribery... If you took 1 1/2 days to reach your destination, the question would be whether or not you were late... just as it is for the environmentally conscious employee who bikes to meetings & is often late (yes, I'm from PDX). But if a day and a half in 1st (because of your upgrade) meant you were more productive, maybe your choice was the best for your company?