The size is perfect for carry-on, and easily fits flat in the overhead of an MD80 and on a Boeing 787 it fits standing up on its side. When returning from overseas, I had overpacked my luggage, and used the expandable feature on this bag; I'd been worried it wouldn't fit as a carryon, but it did due to the depth of the 787 luggage bins. On any smaller plane you probably wouldn't be able to use the expandable feature on this and still fit it as a carry-on.

My only complaint is that the wheels are not great; the plastic is very flimsy and will grind down on macadam in very short time.