This, right here.

I went with high-yield for a long time, for maximizing my single-target punch; I was also worried about accidentally aggroing All The Things. Two things convinced me to make the switch to spread: first, I got the Dyson grav photon torpedo, and its heavy mode is slow. Like, plasma slow. The launcher often reloaded before the warhead reached its target. Maddening. And second... well, I'm already getting all the aggro playing an escort, so why not?