If i remember correctly the shield is just a smaller version of the m&p compact.So an m&p mat should be the same like this one Amazon.com: TekMat 11-Inch X 17-Inch Handgun Cleaning Mat with Smith and Wesson MandP Imprint, Black: Sports & Outdoors
I would shoot both and see which you prefer.The 180gr obviously is a little heavier round which sometimes leads to a softer recoil for some folks.I shoot 165gr in my .40 but thats me ya know.
I top off my loaded mag everytime in my Taurus 740. I'll load the mag,chamber a round,drop the mag and add one.Just my habit since day one.My 740 is a 6+1.In my mind that one extra could make the difference!