ditto to all the above.. there is no performance difference with the grills on or off.. its all about how they look. everyone has their own preference.
i really like the way they look with the grills off.. my wife likes them with grills on, so as you could imagine, the grills are on. if you have a 'significient other' in the house helping you make decisions, you might end up with grills on also..
you said you ordered custom finishes?? what did you get, and what grill color?? once they get there, as always, we want pics!!
bigjohn
