Doug,
I used it for ROAR 2 on LH. Since I have found two cheap business class are less than the price using amex. Somewhat surprised, did not think there were limits to tickets on this program but I guess I was wrong. One advantage of using the amex buy one get one free is that one can cancel the ticket at no penalty. Could be a good benefit.
Where are you trying to go. Using a paid for program like Expert Flyer has helped me find routing that I would not have thought of.
