Interesting article by Karl Rehn (a buddy and great instructor) on pocket guns
Some take away points (note the samples are small but its from a class and that sample is all you can get).
1. For skilled shooters - the difference in performance between pocket guns (snubbies) and primary semis was not great.
2. For low skill level shooters - give the limited capacity of the gun and their skill level, the pocket gun wasn't so hot and the probability of good hits was 40%. Karl points out that this is better than no
hits if you don't have a gun.
The semi primary is best but the pocket gun is a bug or for situations where it is the only practical option. Karl concludes you should train with the snubby - good point.
The article isn't about full sized revolvers, I note. But most carry revolvers seem to be snubbies, I would think - as the IDPA survey indicates. I've done the Claude class with my 642 and shot that along with a 632, 642 and snubby Colt Cobra in matches. You can shoot decently but there is the ammo limit (for the more intense - oh, poop, Black swan, incidents).