What's aggravating (other than the price Disney charges for lower-quality luggage these days. I'm sorry but "oh it's cute" isn't worth the markup) is that they rarely sell a mid-size suitcase. We found a hard-shell DVC mid-size suitcase a few years back and immediately snapped it up. But... was that blue Mickey suitcase on the left a mid-size, 24-25"?
For the record, we've purchased Disney-branded American Tourister suitcases that have lasted years longer than ones we've purchased on-property. Same level of use (and most go on the same trips, so it's not just a bad ramp crew being abusive with bags).