Glad to see this thread. I've been thinking the same thing. I find 158 grain SWCs around 800-850 fps to be the most accurate round out of my j-frames. Doesn't kick too badly, very cheap to load, and I shoot a lot of them.
If it's true that shot placement is the most important element (and it is), then it makes a whole lot of sense to carry the round I shoot best and most frequently.