Several of us have been using them since before they were commercially available. Use them nonstop (there’s one on top of my truck right now). They are very water resistant, and quite durable- have had no tears, rips, or punctures. I do not baby gear, it’s just a bag to me.
I’ve got the 4000 and 7000. No complaints. Have quite a few miles on the 4000 and it shows very little wear. Actually carries quite well as a backpack if loaded with a little thought. No issues as a carry on.
I have 2 of the larger I use for flying with all my gear. They have probably been on 30+ flights with no real signs of wear. Really comfortable shoulder straps and very water resistant, especially if you keep them zipper side down in the rain.
My 7000 has been on 10+ mix of private and domestic flights and 1 international. Really good duffle. Carries well. Mine has little to no wear on it. Would for sure buy again.