Has a low profile which actually makes it possible to get this bag on full flights when their checking most of the larger carry-on bags at the gate, but doesn't sacrifice space. You will have to check it at the gate for the really small regional jets, which can't handle anything bigger than a purse, but otherwise you should be good as long as you don't completely stuff this great bag.
This review was written in the old system and had content requirements that are different than reviews written today.