I bought one of the larger Kirkland Signature bags at some point. The bag worked great on many trips, but then I cinched it down too tight one time. This broke some of the plastic to hold the cincher together. I returned it to Costco and exchanged it for the same bag, no questions asked, a year and a half after I bought it. I've been using the new luggage piece for going on a year now without any issues.

With all the abuse luggage gets, having Costco's return policy is a great asset.