Would Heinrich rather carry a Luger or a Walther?
You might have to ask Heinrich, and Florian, and Erich, et al. I'll bet no small number of G.I.s would have perferred a .38 revolver to the M1911A1, but nobody asked!
I've never even held a P-38, so can comment only on my dislike for DA/SA triggers, but the Luger is, contrary to what you hear, something of an ergonomic nightmare. I suspect the P-38 feels much more "modern" in the hand, due to the shape of the grip, but it has the same awful sights as the Luger. I'd chose MY Luger over any P-38, but would probably choose a P-38 if it were a choice of random examples of the two types.
I'd think most soldiers, cops, etc., would choose the gun that they have, if it works, over anything else with which they are not familiar.