I've got a customized S&W Model 19, 2.5" barrel. It is very accurate and, with 110-gr. JHP's, not unpleasant to shoot.
The problem is this: it's a holster gun, not a pocket gun, and as such it requires a covering garment. If I'm going to wear a covering garment, I'm going to be carrying a full-sized 1911 or, at the very least, a BHP.
The up side is that at 2.5", it's a compact and hard-hitting package. But think about what ammo you'll be shooting. 125 JHP's rule the roost as far as self-defense rounds go, but they are pretty mean out of my 686 and the Ruger GP 100 I used to own. Touching one off in an enclosed space, in a snubby magnum, is asking for permanent ear damage. So you drop down to a 110-gr. JHP. But isn't that the same as shooting some 9mm Cor Bon? So why not pack the BHP or a Glock 19? Similar cartridge, more shots, easier to reload, carrys flatter.
If you're talking about a S&W 640 or similar "pocket" .357, I say go for it. I've thought about buying one myself. Loaded with nothing more than 110-gr. JHPs, or Federal's new 130-gr. personal protection load, it would beat my 642 any day, and probably most other pocket pistols. Heavier, yes, but hard-hitting.
But once you go on the hip, I'd rather carry a 1911....
Just my .02.