First of all, the Shield is practically unobtainable.....S&W will have a hard time meeting demand. It is not legal for sale in Maryland until the middle of July.
Why shoot +P in a small frame gun....sure it will be fine, but continued use )if you are a frequent shooter) will surely have negative effects on the gun. If you wanted more power, you should have bought a .40. That being said, I am certain that the rounds will shoot fine. Be certain to try everything you can buy, in your particular firearm, to see what groups the best (use a rest of some kind). Then, use that as a preferred load (unless it is a handload or one that is unsuited for defense) for personal protection.
Terry