This is the sturdiest binder that you can find. My son went through a new set every month because they were not strong enough and would fall apart or the steel binder would not close after a while. This binder is well worth the money. The rubber around it makes it easier to grab and the edges don't end up falling apart. This is the only binder I will ever buy.
This is the second of these binders I have purchased. I use them with sleeve protectors as my cookbooks. Unfortunately after frequent use the rings do start to spring and not close completely the the pages catch on the rings.
The D-Rings make it so easy to turn the pages to get to where you need to be in the notebook. It actually holds more than a regular round ring because of the shape.