I got into a debate with someone about the two. I've tested them out and saw no difference. I think the Itech is a bit overrated for its ranking. It seems people think its good because its on NX weapons and it has a rank requirement. When I finally unlocked it I got it and the only difference I saw was the decreased zoom. I'm an Assault Rifle user and I prefer a bit more zoom then what the Itech and provides, but people say that the Itech decreases recoil and increases accuracy, which is not true in the least bit. It states that the Itech does improve accuracy, but I see no change when using different weapons.
My vote, Advanced Combat Optical Gunsight.
Subject: Itech or ACOG? 
