I say be comfortable and proficient with what you carry. I train with both. If I was an LEO, and had the choice, it would be a Sig P226/9 in .40 or 9mm. But if I had to carry a revolver, I'd be fine with that too. Any number of good revolvers I'd carry, too....Python, S&W 27, 657, 686....
Accurate aimed fire, as mentioned, works best. Be trained and proficient, and hope you never need to use it.