Best I could find for my desired usage.
Used this bag for a couple trips so far, still looks brand new. The removable backpack straps are a big help when carrying more than a few hundred feet, but I would not want to go more than a mile using them. I have wonder about the long term durability of the top backpack strap attachment point, if anything goes wrong I think that would be it. This is my second one, I might try to get one in each size. Definitely recommend, seems tough as nails, if I manage to break it, I'll update.

Perfect
Purchased two bags for our Kilimanjaro climb. Very sturdy, have lots of useful straps - you can carry it on our back as a backback or in you hands. After 6 days of extreme conditions, still looks brand new! Pricey, but worth it.

Next Level Duffel Bag
After reading such incredible reviews for this duffel bag I couldn't resist purchasing it before a trip to Asia. I chose the medium for my three week expedition and it was a perfect fit. I was able to use it as a carry on but still fit everything I needed. Good quality material with a carrying system that works really well. It's really easy to put the should straps on and off if you'd like to check it instead. The zipper is interlocking as well which I appreciated.

Great product
This bag is very durable for travel. You can use this as a "back pack" or just a duffle bag. Knowing how the airline company handles the check-in luggage, I was happy to purchase this bag.

Great bag for little 3-4 days trips. Great quality. Easy to hold like a duffel bag or fits on shoulder like a backpack nicely. Highly recommended. I'm a civilian contractor for the government working in Afghanistan and I bounce all over the place for a few days at a time and this bag works perfectly.