To say that it is just a really hot 9mm is relative. A 9mm +P+ of the same weight (124 or 127gr) will net you ~ 1250fps or so. As long as it is loaded like it was intended to be the 357Sig is roughly 200fps faster. That ain't chicken scratch to me.
"...there's a man with a gun over there, tellin' me I got to beware..."