Yea, I just cant commit to carrying two heavy plates.
Just carry one and dont get shot in the back.
Op curved plates are supposed to further mitigate penetration by not allowing the rounds to impact at a 90 degree angle. Its the same reasom you see angled armor on APC's and tanks. One thing about the AR 500 plates is that the flat plates are ampedixtrous(sp) the curved ones are not so when you order one you have to make sure to tell them weather or not you are left handed. Fwiw I plan on ordering a plate or two myself.