The dirtier they get the quieter they get. My only advice to you is this: If you get one to take apart and clean, you may want to consider going all stainless because some of the good cleaning solvents are hard on aluminum. Tactical innovations makes one called the Quest that is all stainless and comes apart for $399 and after much research and debate, this is the can I just ordered recently myself. Just my 2 cents.
I"ll keep my freedom my guns and my money and you can have the "CHANGE"!