Flat guns are usually easier to carry, and nowadays are often about as reliable as a revolver. However, J frames are not exactly a burden, either, particularly in a good holster. With a good belt and a Don Hume JIT or better, they are effortless. With some pants pockets and the right holster, they can be very comfortable and particularly available. Since Richard Rosenthal (RichCapeCod) of Rodman's Neck got S&W to put 1/8th inch front sights on the J frames, they have been just as good as the autos, which weren't so great in the old days, either.
The big advantage of the J frame over most or all autos is the handling safety. I seldom load or unload guns in the house, but when I do, I would certainly rather do it with a revolver than with an auto. Same goes for holstering. Striker-fired autos and enclosed-hammer revolvers (new Centennials) are particularly dangerous. Most of us will spend a lifetime and never need a gun to repel boarders, but there is a tremendous amount of "adminstrative" gunhandling in a lifetime, and no matter how low the probability of an error, it needs to be lowered more. One of the more significant ways to do this is to handle a revolver rather than an auto.
P.S. For my hand, a SB Airweight or steel J with a Tyler, or a RB steel J with a Tyler, is MUCH more shootable than any small auto. Get as large as a Kahr K9, and the advantage disappears, but that Kahr is heavier and still striker-fired. For everyday carry, I prefer the simpler safety of the revolver.