UPDATE: I finally went on my trip.  I bought a total of four of these duffel bags, but ended up taking three, plus two smaller bags. So far, they traveled in a truck, 2 Ubers, 1 hotel shuttle, 2 airplanes, and thru baggage claim...and a yellow cab and they all made it to Mexico City all intact.  No rips, nada.  I'm impressed.  I've added more photos to show the bags in their original state packed.  They all weighed about 40lbs at the airport.  They were pretty much packed and I'm sure exceeded the checked baggage limit size based on my measurements, but I didn't have to pay any oversize fees at the Delta service desk.  They didn't even look at them twice.  Highly recommend these if for no other reason than a good bag to use for storage.

Please note: I stored the shoulder straps of each bag in one of the outside zippered pockets.  That's when I discovered that the fabric (seat belt material) that is made out of the handles actually extends all the way to the bottom of the bag and is double stiched and taped and sewn with a separate piece of nylon, so those handles are hefty.  The whole time I thought they were just sewn to the side of the upper bag because that's all you can see from all the images.  But, when you unzip those exterior pockets you'll see the extra craftsmanship.

ORIGINAL REVIEW:
Wow!  Very roomy bags.  Upon opening the small boxes they came in, I had my doubts and they initially appeared to be just regular size duffel bags.  But, after I shook one open it expanded to a mega size.

I purchased two of these to use as checked bags to transport a LOT of stuff I will need for a 9 month trip.  Mainly a lot of cosmetic bottles,  cleaning supplies, a heater, fan, slow cooker and a lot of other stuff.  I find that no matter where you go having your own cooker, personal fan and heater is necessary, because rooms are either too cold or hot.

These bags aren't very cheaply made in my opinion (even though they are made in China).  I thought the nylon was stronger than expected and the zippers are too.

All the hardware is metal, not plastic.  Can't wait to use these in 3 months.  I would recommend using bread bag ties to tie the two main zippers together, which is what I do with other pieces of luggage to prevent them separating in transit.

Locking any soft sided luggage, in my opinion is a waste.  If someone wanted inside, they just penetrate the zippers or cut the fabric.  But, bread ties work great to lessen the chances of an accidental opening.

I update many of my reviews and I will come back and give my 2cents on how they worked out in the wild.  But, there's no reason to give these bags nothing less than 5 stars.

Note: I purchased the red color, and it's not fire engine red, but more burgany/maroon in color.  Which is a good thing.

I added a photo to show how large these bags are.  I stacked both of mine on top of a Patagonia Black Hole Duffel 120L size.  Look how much bigger the Amazon bags are.  Those
120L black hole duffel bags are huge.  People use them to go to Mt Everest base camp.  Hope this photo helps in comparing the size.

Before I forget, the only thing I can see Amazon doing to make this bag even more awesome, is adding a shoulder pad to the strap.  I already have several extra pads from other bags that I plan to slide on these existing straps.  I will only be using the straps to move from a taxi to just inside the airport terminal to the checked baggage desk.  So not a biggie.