One thing I love about my two 66s, they're extremely accurate with .38 special. Not all .357s are. I've owned a Ruger Security Six that wouldn't shoot a wadcutter into 3" at 25 yards from a rest. I'm a stickler for accuracy and that didn't make me happy. I had a Smith M19 that bettered that by an inch, but my 3" 66 puts 'em into 1.5" and my 4"er will make a one hole group if I can do my part that particular day. A ransom rest and lord knows how tight the group would be. It shoots .357s well, too, of course.
Now, most folks would think my accuracy fetish stupid, but in the case of my 4" 66, it's a hiking gun and could be needed for small game. I've shot squirrel with it, very accurate for that. Hunters and hikers who might need the gun for survival desire a higher level of inherent accuracy from the gun than do folks whose only desire is self defense. That Security Six was very accurate with .357s and adequate for self defense with any load, just that I needed more. That's why I still have my M66s and the 19 and the Security Six are gone. AND, the versatility of the .357 to shoot the light .38s (all .38s are light compared to .357 loads) is what makes a .357 revolver so useful to the outdoorsman.