It is VERY aggressive, but gentle when it wants to be. Keep it below 3.5k and it is super quiet. Hit WOT or down shift hard and it comes to life.
well i have the hks hipower on my ls. kinda loud but i like it, although it gets really annoying driving on the freeway but thats why we have music to drown it out lol. sounds sexy as hell smashing thru the gears tho