Seriously though, the .40 is considered to be much better than either the .38 or 9mm by some, though it's a lot closer to the 9mm than the standard-velocity .38 loads.
Both the .38 and 9mm seem to be just slightly more accurate in my experience though, but not by much. And recoil is a little... sharper?... with the .40. Nothing uncontrollable or uncomfortable, but more evident than with either of the others.
The worst down side to the .40 is ammo price. It's a bit more expensive than the others, at least around here. ( I used to reload for mine. )