To my mind the P3AT is a different category of CCW than a .38 snubby like the 442. The 442 is a fairly deep concealment gun. It weighs about 1 lb loaded and an average sized man with a quality holster can pocket-carry it pretty inobtrusively. The P3AT offers concealment that's a level deeper. You can hide those ingenious little things almost anywhere.
That said, I'd feel less well armed with the P3AT. When I test drove one (briefly) I found it hard to shoot effectively. The design still seems to be dogged with some reliability issues -- just read the forums, or gun mag reviews. Plus, there's awfully good .38+P snubby ammo on the shelves, whether you prefer wide, soft 158 gr lead hollowpoints at 800 fps with good expansion and penetration, or new stuff like the Speer 135 gr Gold Dot JHP.
The .38 revolver is more weapon, but the P3AT can go places that even the snubby can't.
A closer match for the 442 is a "duty" .380 pistol like the PPK or the Bersa. Same size as the 442, same concealability. The revolver is several ounces lighter, extremely reliable, and hits harder. The .380 holds more rounds, is faster to reload, and if it has a good trigger (i.e., if it's a Bersa) it will be easier for most people to shoot well than the snubby.
I think it's a toss up. I favor a snubby because in a defense situation, I would rather my first shot on target be a Winchester or Remington 158 grain lead SWC +P hollowpoint than anything that comes out of a .380 barrel -- but there are strong reasons to favor the .380s too.
And I would probably admit that a person who has a small, high quality pocket 9mm like the Kahr minis or the Rohrbaugh has the best of all worlds. Their only disadvantage is cost. Quality small 9s cost a lot more than a J-frame snubby or a Bersa.*
* This is why I roll my eyes
when people ask, "Why would anyone carry a .380 when they could get a small 9mm?" Dude, because you can get a Bersa new in the box for $250 and have a solid pistol. Cheapest price for a NIB baby Kahr on Gunsamerica right now is $549.