I have a 640-1 and a 442. Obviously, the 442 is much lighter and is easier to forget that you are wearing it. Both are good; the .357 is hotter, much more recoil but who cares? If I were in a more dangerous area, perhaps I'd carry the 640-1 more than the 442. Or maybe both. Right now, I always have the 442 On both guns, I use a Barami HipGrip for IWB carry. Very cheap, very inconspicuous, very efficient. I've used them for 30 yrs at least. I seldom use a real holster for any IWB carry, although I own them.
Sonny