I'm a small guy so a 642 in the pocket seems bulky and can actually be a bit uncomfortable. In jeans the grip on my 642 peaks out. So in jeans or very light weight pants, the LCP or my P3AT is what I carry. I would rather have the J frame though. Both my LCP and P3AT are reliable but I do like the 5 rounds of .38 +p over the 15 rounds of .380 (that's w/the Keltec with the 1 round extension on both mags).
Since I carry the spare .380 mag in the pocket in a leather mag holster, I know the reload is going to be long.
So I try to find some way of carrying on the waist with something larger. My problem with summer is that I've never been an "untucked" kind of guy and don't even have many cloths that work for me. I don't ever wear T shirts.
So I miss gun's like my New Agent in the summer!