Great, great bag - waterpoof, yes
Over 2,000 mile trip to Florida in pouring down rain on the way down. Everything stayed perfectly dry. Easily held 3 mid size suitcases and 2 kids suitcases.  Bag conforms to what is in the bag, so after emptying you can fold up for storage.  Nice design and no issues so far.  We used bungee and tiedowns to strap bag down to cargo hitch carrier after putting in the suitcases and zipping up.  Zipper goes almost all the way around (like a suitcase) which made it easy to put in suitcases, although it helps if someone holds it open as like I said it collapses down with nothing in there.  Would highly recommend this if you need maximum storage, durability and waterproof.  You can find cheaper bags, but I prefer the quality of this bag.
Rating: 5 stars