I have a S & W Shield in .40 caliber. I do enjoy the caliber size, but am thinking of going back to a 9 mil just to have more rounds in the magazine. Currently I only have a 6 round and 7 round magazine, and its not a lot when getting overran by a horde of Obama voters.
I liked the video of the Springfield XDM with 19 rounds in the magazine. I would trust the 9 mm round to be a show stopper for bad guys; just ask Trayvon Martin in Florida. He took a 9 through the heart and it stopped him from killing a citizen.
During combat in Iraq, an American soldier was moving through a battlefield with heavy smoke, with his 9 mm Beretta at the ready. All of a sudden 3 Iraqi bad guys accidentally ran right into him and they were one behind the other. He fired one shot into the lead bad guy and it went through all 3 of them. I can't remember if they were all killed or not.
A friend of mine has a Shield in .40 he offered to sell me for $450. Has one clip fired thru it.