The more you gut your exhaust, the better your engine is going to breath, and it will help you out on the high end, but down low you will sacrifice some bottom end torque, and maybe hurt your 60' times, so it's a trade off. Completely stock Crossfires have gained as much as a 4/10's improvement with a CAI.
Our cars don't have the explosive power the SRT's display, nor do we have a steep enough gear to warrant drag radials, IMO. A good set of smaller diameter 17" or 18" rear tires would surprise you.
John (JHM2K) as you pointed out in Cross725's other post, You're not a drag racer, and that's not what you purchased your XF for. Now there's nothing wrong with that, I didn't buy mine to drag race either. But Cross725 wants to take his car to the drags and wring out the very last ounce of performance he can.
So why be embarrassed with a 14 sec. ET when an SRT turns 13's and even 12's? The two cars are simply in different classes. Just like a 427/435 hp Vette wasn't in the same class as a Vette with a 327/300 hp. But I bet the small block owner had just as much fun running mid 14's and racing other cars (in its class), so there's a place for everybody.
When I raced nearly ever weekend in the early 70's, a lot of guys use to race bracket racing. They'd simply dial in what ever ET they projected their cars would run and have at it. More ofter than not, the top eliminator was some old guy driving a 1966, 6 cyl, Biscayne with a powerglide turning in the 18's. I bet he was never embarrassed going home with the money every Saturday night.