True Flow Intake?

From : dc hunt

Q: i am getting a 2007 dodge ram 1500 hemi and i am looking around for an intake system for it. i have read a lot about the true flow system and was wondering how much louder than stock if any the system is my father-in-law has a k&n cold air intake on his dakota and it is very loud. i noticed the true flow setup still uses the stock air box and was wondering how loud this setup is and if it makes any whistling noise. thanks! dh .