I purposely bought "heavy duty" because I needed something strong and 10 minutes after I started using the binder one of the 3 rings opened up and my documents started to come out of the rings. It is obvious that the quality is not up to what it is supposed to be.
I've had a lot of experience with binders over the years. This one seems to handle almost 2" of paper quite well. I assume it's due to the design of the rings (round rings are not the greatest as you may know). These have a good D shape and seem to handle the aspects of opening and moving to different sections as well as I've seen with other binders. And the rings meet evenly another source of consternation when they don't and paper hangs up (and you have to try to bend them to meet properly). All in all a good binder.