FCfree makes a good point. I tend to work between a minimum and a maximum balance. When I have plenty of miles, I'm more inclined to capture some value with a special long weekend trip -- something that might be very inconvenient to do with money at the time, but is a nice thing to be able to do with miles. These are always standard awards or at even lower, promotional levels. We often end up with FC upgrades, which is an added bonus. I don't really consider it "burning" the miles so much as just seizing an especially good opportunity to use them.