I carry a j-frame when I am unable to dress around a larger gun. When I can carry a larger gun I have found that I tend to carry pistols more than revolvers, though I can and do carry one of three medium framed revolvers.
I grew up shooting DA revolvers, my first handgun was a Smith Model 28, and I regularly compete in IDPA using one of my many revolvers. In short, I am a huge revolver fan. However, I have seen revolvers including my own fail, normally with the cylinder locking up, caused by faulty ammo, a lose ejector rod, or crud under the extractor star. My carry pistols have over a thousand rounds through them each (some have several thousand rounds through them) and they have never failed, period.
But the reliability issue is not why I carry pistols more. I have found pistols to be more size efficient than revolvers, so I generally carry them more. Also with the price of ammo and the scarcity of 38 special ammo now a days (one day someone will explain why that is true to me) I find that I shoot my pistols more often than my revolvers so I am very comfortable carrying a pistol for self defense because I get plenty of trigger time with them.