Good for CZ! This was a problem with the RAMI for me. I'm going to stop in the shop to see one when they arrive.
Now, just to be picky, there are two other solutions that would have solved this problem and not introduced the extra switch: (1) Devise a feature which closes the slide when a new magazine is inserted. No gun has this feature designed into it, although you can force some guns to do it by slamming the magazine home. It would provide the fastest reload possible. (2) Make the original pin into a button which would drop the slide.
Their solution to the problem at least allows the user to lock the slide back on demand. Locking the slide back is a common way to hand a gun safely to another person. It is also a requirement in most of the classes that I've taken that the gun be put down with the action open. Baring a slide stop pin, the user would have to insert an empty magazine to lock back the slide.
