Well, I own a Glock 9mm and a .38 Spl snub (6 shot).
I tried carrying for the first time recently, now that I have a decent holster for both (the guy who visited the States came through on that one!
).
Admittedly I've only carried the snub, and admittedly I come from a no-gun culture....
...but I did not feel like I couldn't handle any problems that came up through lack of fire-power. It would be more a case of lack of practice.
When I was out and about it occurred to me that I carried enough in that holster to end six lives and that sobering thought sent a shiver down my spine. It really made me fervently hope that my snub would only ever leave its holster at the range...
The .38, whilst less potent than many other calibres, is nothing to be sniffed at, IMHO. In other words, its the platform I can shoot most effectively, rather than capacity that would decide which I carry.
I've yet to carry the Glock, and I'll give it a go to see how it feels, but local laws on the condition 3 carry of semis means the snub is still the better option...