This bag weights only 2 lbs 3 ounces, with most of the features you'd expect out of both a duffel and a travel backpack.
Eagle Creek added smart features for saving weight. For example, the backpack shoulder straps are unclipped and attached to eachother, which forms the single cross body strap.
Unlike many other lightweight convertible bags, the Go Duffel has both a sternum strap and hip belt for added comfort and support when worn as a backpack.
There is no sternum strap or hip belt to help you carry the weight. It can get uncomfortable when worn as a backpack for long periods, especially when heavy.
The entrance for the bag when used as a duffel is barely large enough to get a small pair of sandals through. For any items that aren't small, you have to use the top load/backpack opening.
Not a great option if you're looking for a pack you can wear while exploring the city.
There is no hip belt or hip strap, so all the weight of the pack will be on your shoulders. The shoulder strap padding is fairly minimal, causing them to dig in.