Some things never change, or at least that is what I thought. The old Stanley 10-099 utility knife has been around forever. But in the past few years there have been a bunch of new twists on it. One of them is the folding utility knife. This craftsman model flips open just like a regular lockblade knife. Flip the lever up and the side rotates down so you can change the blade without any tools.
But this flash comes at a price... There is no room for spare blades which is almost a fatal flaw. The aluminum handle is filled with dimples for drywall mud and other stuff to hide in. You can't just wipe it clean. And last, the whole blade is always exposed when it is open. The retractable blade on the Stanley allows you to extend only as much as you need so you can set the depth of cut allowing you to easily score materials.
The folding knife is smaller and flashier. If you work only with clean materials it would be a great choice, but for drywall and throwing in the tool belt, the venerable 10-099 is still champion.