I respectfully disagree. When I was trained to qualify with the M9 in the Corps, the control we are referring to was definately referred to as the slide RELEASE, and we were trained to use it as such. Now, you may be correct that Glock departed from the standard use of this lever, as a simple Google search revealed that there are references to this control as both a "slide lock" and "slide release," but if you are correct referring only to Glock pistols, then this is another mark against Glock. If you are supposed to use your weak hand to move the slid back to reload, what happens when you're hit in the left shoulder and your weak hand is useless? I received training on the one handed reload just in this circumstance, and you most definately use the SLIDE RELEASE to return the slide to battery after you've gotten the fresh mag in the gun. The Glock, with the factory (as you call it) slide stop, is, IMO, to small and being flush against the receiver, too hard to quickly and reliably activate under normal circumstances, let alone in the heat of combat when you've been wounded getting the pistol reloaded quickly is the only thing that might save your life from the guy closing in to finish you off.

Mike