After reading through this whole thread, I find that I like the idea of a MD. I have no delusion that I will use the feature to disable a weapon in the midst of a firefight, but I like the idea of being able to render the weapon disabled or fully enabled (with a round in the chamber) with a simple mag insertion or removal. There are several scenarios where I think this could be useful. For example, I've toyed with the idea of OC (open carry). But I'm a bit concerned that someone might try to take my weapon and use it on me. If the mag is out, no problem. And I could fairly quickly re-arm it with a quick mag insertion. Given how slow I am drawing from concealment, I bet I could draw from an OWB holster, and insert a mag more quickly. That would be about the same speed as Israeli Carry, but with IC, someone could still use the gun on you.

And given all the Glock ND's from things getting caught on the trigger while re-holstering... mine also has the manual safety. ND's have occurred from a string from a windbreaker getting caught. And with a manual safety, I feel that I can safely lighten the trigger pull, too. A light SA trigger is considered safe on a 1911, right? So no, I don't think that the OP is stupid for wanting this. Frankly, I think that it was a mistake for S&W to remove the MD from the M&P.