Use the knife with sniper is a lot of fun but theres one thing that bothers me when using the shadow stab perk.  the camo cloak always runs out a little to short or one of my perks cancels camo cloak right before full charge and ill take damage.  I propose removing a little bit of melee damage from the perk, maybe down to 15% from the current 20% but add that camo cloak canceled by perks like ambush that immediately cancel camo cloak or charging up of weapons.