For bipedal self-defense, I don't see advantage of 10MM vis-a-vis .40 S&W. In fact, I'd take a hi-capacity .40 S&W over a 10MM every time if we're talking bipedal self-defense. As a trail gun, I'd rather have a 10MM.
If my 40 trail load didn't do the job with 12 shots, I didn't need a cartridge burning a few more grains of powder. I needed a different class of cartridge altogether.
