Some comments on upgrades: upgrading myself to business class cost me 25K miles each way -- quite a substantial chunk of my balance. But, the travel earned me miles back: 7K miles each way. Further, due to my elite status (silver) I get a 50% bonus in miles, meaning that each way only cost 15K net. Since I've been doing about 1 long flight a year (i.e. 12+ hours), and also do a couple of "short" hops across the atlantic, it seems to be roughly "free" to do this; certainly, compared to the alternative use of miles (buying more flights for free), it seems like a more valuable use, at least when you compare the raw cost of the options. And I'm destroying the environment about as much either way.