I run em and I like em,'' have a rattle to them at idle'' I really can not speak to that cause between the sound of roller rockers and a lumpy grind tossing the car from side to side , I have never heard or experienced that . I do have a cam button installed maybe that elements this '' rattle '', and the fix in so to speak..
I am always ask what the cam is so they are dis-stink sounding and radical, gets the ears listening .. hope this give you some more information to chew on
Obtw: too lumpy will not allow for the use of power brakes, a separate vac supply will cure that ..