Hold opens

[sdmark777]

Actually if you follow the most current tactical handgun training you no longer use the slide stop to release the slide after inserting a new loaded mag for a mag change. Instead, you grasp your offhand over the slide, pull to the rear and release. This current style is preferred because it can be difficult under stressful combat situations to hit the release, blood, water, mud, small muscle memory. Grasping the slide is considered more reliable and large muscle memory. So since the Luger does not have a slide release like the 1911, it is all ready up to speed for the modern technique of grasping the slide or in this case the toggle. Also, you don't necessarily have to grab the toggle by the two ears when it is help up by the hold open. You can strike the front of upright toggle with the palm of your hand from muzzle rearward. A good strike is all you need to move the toggle rearward slightly, releasing the hold open. This allows for very fast reloads.
So yes, the Luger's hold open is an advancement in design and necessary for expedited reloads and general handling. (Even though I have been trained and practice the new tactical technique of grabbing the slide on 1911's, I still often revert to using the slide release. After decades of shooting the old way, I feel the muscle memory is already imprinted on me).