... and I find it's much easier to do upside down and for me, LESS chance of anything being off kilter. I count on gravity to drop the wheel evenly into the dropouts without worrying about the weight of the bike leaning over and making it wonky. It's difficult with aerobars and computer, but for me, the easiest way to do it, although I can do it both ways, and usually don't bother flipping for the front wheel.

To each, his own...