Originally Posted by
ExXB
As long as your bag is not overly big, and you can put it into the lockers unaided you should be OK. Having a slightly smaller bag that will fit under the seat gives you an option on full flights where locker space is a premium.
This.
If you try to bring a shrink wrapped load of clothes, blankets and small child, or if you give them a reason to look, then you'll be checked.
If you have a standard carry on (without the expansion pockets which make the bag obviously bursting at the seams and twice the size), you are likely to be checked.
We brought back 15kg or stone ornaments in a wheely case and they didnt check as the bag was small.