I wouldn't dismiss duffle bags so quickly. I have an eBags eTech that has good structure. It's a drop bottom, so the bottom half has as much structure as a suitcase. It has sidewalls that fold down so the duffle bag stores flatter and fold up to give the upper part more structure. When my bag is empty, it looks like it is packed full. Absolutely the best shape I've found for presents, especially bulky ones. It's light weight, stands upright, even when full, and rolls really easily.