My #1 rule is that a suitcase will always break down when I am on a trip, at least 5,000 miles from home, and far from any warranty repair center. I've needed urgent repairs in at least Stockholm, Tokyo, and Manila.
So I pick a case that is easy and quick to repair locally, even if not under warranty. One big way to get this is to buy a case held together with bolts rather than brads, so it can be mostly disassembled and assembled with only a screwdriver. Until recently, B&R didn't do this but now they do on some lines. Hartmann and (the late) Andiamo do too. Forget TravelPro, Swiss Army, and cheaper brands like Samsonite, Delsey, etc. Quality of construction is way more important than a label, especially one like Vuitton that yells out "steal me."
Shipping to the B&R repair center isn't a big deal for me since luckily I live about a 40 minute drive from Half Moon Bay airport, the obscure location where it is located.