I'm running into the same feeling with Crisis that Yahtzee talked about in his review. I too am big on stealth and I have a great fondness for sitting in some bushes, invisible to my enemies, picking them off from a distance one by one. He seems to go for the stealth kills more whereas I tend to pick people off with well aimed shots at long range but the issue remains the same. I'm playing on the hardest difficulty and the game is piss easy because of my pansy tactics.
I sit really far away cloaked with my silenced assault rifle. I can fire about 3 or so shots with it, retire to some cover for a second, and recharge my energy bar incredibly quickly. Rinse, repeat until everyone is dead, then move towards the objective, cloaked of course. Not knowing where I am the enemies are content to either search for me slowly or stand perfectly still. Even with my assault rifle, not sniper rifle, getting the well aimed one hit kill headshot is not especially difficult, and even when I royally fuck up and my cover gets totally blown relocating myself while cloaked and waiting for a moment will return them to their slowly walking behavior pattern.
I almost feel bad playing the game, knowing that the developers put tons of crazy stuff in the game that I never get to use. I think I've killed two enemies with an object as two guys were standing right next to a car and I wanted to try the power kick. I've killed a decent number of enemies with the silent kill attack but that's still in the same realm as the headshots. I've never killed anyone by throwing something at them or using the neck breaking throw attack. The game was way more challenging before I found a silenced gun. Since then I've just been doing the same thing over and over. The cloak is too good. It's almost a game breaking mechanic. I know this and yet I never stop using it. I'm too tactically oriented to stop. The run and gun approach seems too reckless, and therefore I stick to my sneaky shenanigans. It's really just too powerful though.