The cardboard cover is barely sufficient for the standard version, the increased size and added zipper make the cardboard too weak for the zippered cover, giving it a somewhat flimsy feel

In any case, the zipper itself seems to work all right - that's the best thing about the zippered binder

I can keep pens in it, nothing falls out on me, the pages turn beautifully, and the zipper is pretty solid.

Good zipper