When you're packing for your trip, do you go with placing trust in the airline to get your luggage there or do you pack as much as you can into your carry-on bags? Southwest allows a carry-on plus a second bag as long as it fits under your seat. Should I put as much as possible in these, and deal with inconvenience of two bags to deal with at layover, or just go with lighter carry-on presence and trust them to get my bags to my destination?