Besides protecting the discs and minimizing storage space, a DVD storage soutions has to be ergonomically correct and efficient. That means the DVD has to be accessible quickly and easily.
Many storage sleeves use a "bull horn" cutout that makes it especially difficult to re-insert the DVD because the disc frequenty gets caught on the flaps of the cutout.
Another often forgotten aspect is the orientation of the opening. Most sleeves use a top opening beause it is the most simple way to manufacture the holders. However, in a typial usage scenario the storage container is held with one hand and the other hand will insert/retrieve the DVD. The most natural movement is to slide the DVD in/out horiontally. This requires a side opening that can only be found in DVD Storage Sleeves from DiscSox.