Same here, when I listen to the radio the best sound I get is Bass +9, Mid -1, Treble +9.
When listening to my iPod (iPod EQ beging set at "Latin" for a bit of bass and treble boost, best setting so far) I sometimes have to turn down the bass setting to +7 or the bass becomes too present at low volumes, at higher volumes it is perfect.
This sound system is really good and very impressive.
The only problem I have with it is that I can hear a "rattling noise" when I listen to some types of music with big bass in it. I've been able to isolate this noise source very easily. It comes from the rear center safety belt roll in the rear right upper side of the trunk (behind the plastic cover). The longer I extend the rear center safety belt, the lesser the noise so it might just be that the tension I'm creating when I do that removes some "slack" from the roll mechanism and stops the noise. If I fully retract the seat belt in the roll the noise is much more present.
This slack in the safety belt system doesn't seems to be the only one I have in the truck. I also have a slack in the driver's safety belt (where it permanently attaches to the left bottom of the driver's seat (near the door). I'll have them fix all of this at my next oil change.