I have an old-school hard side Samsonite. With no access to laundry, I can pack for 2 weeks in that bag. With access to laundry, I can go indefenently with what I can fit in that bag. It holds up well to all sorts of abuse, including being used as a stepstool, chair, and being tossed around by the Kew Runner drivers in New York. (If a bag can survive the Kew Runner, it can survive anything.)
After 9/11, pax were limited to 1 bag and one 'personal item', unless you were in uniform. When I was commuting, I did NOT want to have to commute in uniform all the time, so I only took my small kit bag and my Samsonite. No purse, no cooler. Before 9/11, I used to carry food for my trips in a small soft-sided 6-pack sized cooler. With that cooler and a few cans of soup and a can opener in my bag, I could go a whole 4 day trip without buying any food. Saved boatloads of $ AND lost 10 pounds!