If OHKs are your concern then headshots are the least of your worries. Pretty much every offensive move that you can make in Destiny is a OHK unless of course you use your primary. Many of these moves will take out entire teams if your timing is right. Destiny is not made for MLG nor competitive of any kind. Its a casual MP. To make it competitive would require a major rebalancing. Honestly, I don't like the MP because its so imbalanced but headshots aren't the issue. If you decide to buy Destiny you are going to have to come to grip with the fact that the MP doesn't not reflect skill but rather who can drop their OHK option the fastest. I suppose that is a skill of sorts but it's a pretty minor one. MLG won't give this game a second look.