I'm a 40 fan, I have the shield, the standard model and a pro L, I carry or shoot them all on regular basis, The 9/40 thing is been done to death, who cares, they make holes when they go down range, I like the accuracy of 40, I was put off of 9 a long time ago and probably the argument is not valid with the better firearms were talking about here, but I find its easier to reload, the bullets are bigger and the case mouth is bigger, I fumble less with the bullets during reloading and I can turn out 40's and 45's faster than I can turn out 9's, (said I don't carry them not that I didn't have them).
You will be able to knock down steel and bowling pins with much more authority and therefore you will win a match over a 9 all things being equal
I have won more than one match because I get away with a less than perfect hit, But I retain the mag capacity and don't have the bounce of the 45acp,
the shield smacks my hand around with defense loads but shoots my reloads fine, I stay with 180's for everything, My pro 5inch runs like a sowing machine,
Here is My son and I shooting, I had the camera On and the little fella is my 15 year old son
Stage_2.avi - YouTube