An X-pipe is an exhaust pipe in which the two pipes (1 from each bank of cylinders) meet and cross over under the centre of the car. This allows the pulses in one pipe to help extract exhaust gases from the cylinders on the other bank. Your car already has an X-pipe on it but it is silenced. What an unsilenced X-pipe does is allow out more of the sound you have already got with a lot more pops and crackles as well. For the relatively small outlay it's a no brainer.
Thanks sounds good! Only issue is that it would void my warrantywise warranty!