since most airlines charge per bag, needed one large suitcase that could hold everything. Before purchasing this one, I was a little worried about the split design and the divided compartments - would those features not allow for large items, or interfere with over stuffing the thing, etc. All my worries were non-issues packing for a 10 day trip to the caribbean with snorkel gear and hiking gear. A normal carry-on fits in one side of the split roller with room to spare on that side, just to give you an idea of how much space you get. I do have mild concerns over durability of the bag, as it has all material outer. It seems to be thick, beefy material but airlines are brutal with your stuff. No problems so far. The compression straps are awesome as it makes the bag very usable still if you don't need all 4000 cu in. of the bag, and it seems to take some of the stress off the zippers. Smart design that works for me.