All I know, is that when I put my 442 in my hands it feels like home. I shoot it OK and hopefully getting better. It is a natural pointer, fast out of my holster, and seems like it would work. It has a lot of downsides (like capacity, heavy trigger) but I can't explain why, I just like it. I might not have a good reason to trust it, as some pointed out, but it just seems like it has some upsides over a tiny auto. I admit, it might all just be in my head.
From what I can tell the upsides are:
.38 might have the edge over .380, possibly
if a round is a dud, you just keep going
there is maybe some possibility that you might shoot someone with your muzzle touching them, and autos might not fire if they are out of battery
my guess is your 642 feels a crap ton better and more natural than that pistol. It looks like it might be awkward to hang onto during recoil
But believe me, I'm sure the pistol has it's upsides and I don't want to overlook those. But I did vote for the 642.