I've been doing a lot of work travel lately and haven't had any problems with carry-on luggage. I have a roller suitcase that's just small enough to fit through the aisle and also just small enough to fit depth-wise in the overhead compartment of the larger planes (6 seats in a row). When I'm on a smaller plane (4 seats in a row), they just check my bag at the gate and I receive it on the jetway rather than being stuck waiting at baggage claim (though when I travel, I generally try to find flights that don't involve regional jets so that I can avoid the smaller planes with less overhead bin space). I hate checking bags, not because of the extra cost (my company will cover it), but because: 1) I worry my luggage will get lost, 2) I hate wasting time to check the bag, and 3) I hate wasting time at baggage claim. Number one is my biggest concern because I don't have any non-stop flight options from my city to where I travel for work, therefore providing the airline an extra opportunity to lose my luggage at my transfer city.