After much extensive research this was the #1 bag I found and first on my 52nd birthday list! If you know Maxpedition, you know there quality is first class all the way. So when I got my first Doppleduffle, I was surprised to see the backpack straps were stitched a bit off, making the zipper nearly impossible to open & close. I returned it only to receive another in an open box from UPS, but ended up keeping it. Since this review is on the bag, I'll leave out the customer service nightmares I encountered, including more bags that were shippe and billed to my credit card.
If you are looking for a very rugged, well made, bag for travel or BOB Bag, I don't think you'll find a better bag. It's extremely flexible with functional options and just the right size at 3200 cubic inches of space. Packed properly you can hold all the survival gear you need for 3-5 days and for just traveling, up to 10 days or more depending on how you pack. As for FAA size guidelines, its technically just a little to large, however, if cinched down, most airlines will allow it as carry on. I got mine in the monochrome, all Foliage Green Color and it looks great. Plenty of pals webbing for attaching extra bags & pouches or whatever you like. I compared it to the Fliegerduffle, which is basically the same bag just scaled down a bit. The little bit extra space and configuration of the the pocket space and dividers is worth the extra few inches in size IMO. In closing, it has YKK heavy duty zippers and Teflon coated nylon making it very water resistant. Stitching is strong and precise and it allows you to use it as a backpack, or a single shoulder strap, or grab handles at both ends, and lastly, carry it like a normal bag using its comfortable & thick neoprene handle.
I've owned a lot of bags over the years, and can say without reservation, this is the best made, best designed, perfectly executed, and just the right size for 99% of my needs... Not to mention, it's one Wicked Good Looking piece of gear.
If your on the fence about buying it, give it a try. My bet is that you won't be sending it back. Good job Maxpedition!