In my experience, yes. The extra weight does help with perceived recoil, as would adding weight to a firearm as light as an M&P. It can also mess with your transitions if you're used to doing them with the nonexistent weight, since the tungsten guide rod will throw off the balance of your gun forward. But none of it is as massive as the percentage suggests. It's just a small part that, when added with more small parts like your own training and other modifications to the pistol can end up making an overall big difference.