I use the 26 to pack for 14 to 18 day trips and i love it. It is the same width and depth as the 22 so unless it is looked at carefully, one would think it is a 22 and you won't have a problem with it as a carry-on unless you're traveling on a foreign carrier. Even then, you still have a good chance to use it as a carry-on. I also have a 22 and it is adequate for 7 to 10 days.