Yup, all my carry on is legal sized, but not all overhead bins are big enough for the items the airline deem as legal size. The biggest problem is airlines charging for checked bags (in some cases the first, in others the second) which means so many more people bring the maximum allowed carry on (which, on many planes, even with the 1 up, and 1 under rule, doesn't have nearly enough space to accommodate everyone's carry on). I would welcome a system such as I have seen Lufthansa use, where rollaboards get taken at the door, and are back at the door when you disembark - your fragiles, magazine, computer, valuables etc with you under the seat in front (because it is rare you need the contents of 2 carry ons during the actual flight) and the rollaboard waiting when you get off, having been stowed safely, out of the cabin, but still far from any baggage handling/ belts / baggage claim etc.