User blog comment:Argorrath/Black Ops III - Reveal Trailer released/@comment-26535669-20150427155540/@comment-1187559-20150428203128

I still think it would be better if by pressing the melee button you just do a weapon bash, which only does 34-50 damage, so it's not an instant kill on someone at full health so it can't be used out of worry killing. But if you hold it down then it gets out a knife to be an instant kill. That way knifing actually takes a while to achieve.

Also, if someone has a tactical knife, then it can replace the weapon butt with an instant knife, which would make that attachment even more useful, since right now if it's 1 on 1 it doesn't really matter how fast you melee, since as long as you hit you'll kill them.