I use this style binder almost exclusively. Both for archive documents that don't see much light but also for the reference material that I need to see every day. The quality of the binder is well worth the money.
These binders help me organize my first grade materials....Readers and Writers Workshop papers anecdotal records of my students and just about everything else>>>>>>love them!!!
I love the ease of opening and closing the D rings. One push of the lever. It doesn't take massive strenth. The D ring is great. Your papers lay flat. The pockets on the sides are easy to get things in and out with them being cut on an angle. The hinge on the binder helps it to lie flatter. My son is using the 1/2" binder for his music folder and he can place it right on his music stand. It's great.