Kirkland roller bags are too heavy for me to lift to the overheard. Bought a $39 swapmeet bag, and it went around the world twice until the top handle fell off in the hands of a rock-star wannabe doorman at SF Monaco. He was pissed. No tip. Although the zippers held, it seemed time for replacement.

Fortunately I had just picked up a smaller (hard-sided) bag in Italy with FOUR WHEELS!!

Four swivel wheel bags are now my requirement. They don't fall over, they are extremely agile. Mine was less than $100, but I can't find another for less than $500.