For me the decision of whether to pack all in a carry-on or to check a bag (or multiple bags) is a completely practical one and thus is made on a trip by trip basis. My rule is to take what I need for the trip and as little else as possible. Often that fits in a roll-aboard suitcase and a briefcase. When I need more stuff, I pack it and I check a bag. I don't see the wisdom in making a rule out of what size bag you allow yourself. That's just playing games and bragging about the result.