Well, I put a silencer on my S-552...
I did not however put a longer barrel on it...
It now shoots in every possible direction except for where I am aiming.
If I intend on "killing" anything I have 2 choices: A) Buy a longer barrel / B) remove the silencer.
Now, in reality, with the original barrel it did perform well in reducing the muzzle "pop" of the gun but the mechbox and motor still make the majority of noise.
Esthetically speaking, it look great... but if you want to survive, stand directly in front of me.