I used to carry a 642, Seecamp, LCP, and a few other as a BUG until I got a Smart Carry holster and figured out, I could just as easily carry a Glock 26 with a 17 reload, and in the exact same place, using the same type of holster. Havent carried any of the others in a second line capacity since.
The 26, while maybe a little pudgy in spots, is basically the same size as the 642, carries 10 rounds of a more powerful round, has a good set of sights, and shoots like a full sized gun, pretty much out to the same distances they can too. And should I shoot it empty, its instantly reloaded with a 17 round mag, to make up for my piss poor shooting, that made me have to reload.
More realistically, it allows me to hand it off to my wife or whoever, with a "full" mag, as its basically just a short barreled 17 at that point.
I really dislike pocket carry and always found it lacking. The main reason is, I already have WAY to much stuff in my pockets, so, no place to put the gun, and the pants I normally wear, even with an empty pocket, arent any size pistol friendly, especially if you need to draw it in a hurry. As Kleanbore has mentioned, its not user friendly, if and when you really need it.
The Smart Carry's are basically just a "deep" AIWB holster, and easily and quickly accessed, and with just one hand, sitting, standing, and/or moving. I much prefer them, and I can actually carry a lot more gun with one to if I want to.