Thanks for the feedback. So if you could only have one bag, the U121 or U122, which would it be? Are you more likely to be forced to gate check the international size U121 on a domestic flight or the domestic size U122 on an international flight? The U122 is 22x14x9 which is actually still within the size guidelines for some international carriers. Perhaps that is the better bag if you're looking for one size fits all?