Pocket carry is about the only thing that makes sense for a pocket pistol, unless you're up for very non-standard options like ankle carry (not for me). This is one reason I got rid of my 21A a long time ago. I eventually found that a good IWB rig was more all-around concealable and convenient than pocket carry. I still have some dedicated pocket pistols, but they get very little carry time.
My other reason for dropping the 21A was that it was about 98% reliable with the best ammo I could find. Somewhat short of confidence-inspiring.
The Beretta 71, though, was a completely different story. The most reliable 22 pistol I've ever encountered (sample size of three), and the size, while small and convenient for IWB carry, makes for wonderful handling and shooting qualities. Plus, they have a neat history as an actual combat pistol that did some very serious work.