The biggest problem is as they point out - you can't check your bag, and if you board too late they will force you to check it. Then you're screwed. So you get

The biggest problem is as they point out - you can't check your bag, and if you board too late they will force you to check it. Then you're screwed. So you get that unique modern form of anxiety - trying to board the plane before everyone else so you don't have to gate check. You better have a bookbag and nothing else.