improves accuracy, and air efficency, lowers recoil
slows down the rate of fire with the Rt a little
The only downsides to this are the price, and that if you have the rt you have to calibrate the new low pressure parts for it(really annoying). And that it slows down the rate of fire with the Rt a little bit. It greatly increased accuracy, and reduced recoil and noise.
A great upgrade if you have the money.
I'm not sure how much btter the air efficeny is yet, i'll update the review when i find out, but i can tell that it's a lot better already.