Centre crossflow box or dual backbox delete

[hurst75]

Afternoon Chaps,

Total noob here although I've been stalking the forum for a while

I took delivery of an 58 plate A8L 4.2tdi in early Nov and I'm looking to chav it up a bit (sorry).

I love the performance and engine growl but its not quite loud enough.

I've read a few threads re box deletion. If given the choice what would the best option be - centre crossflow box delete or dual back box?

Also in the forum's experience, would there be any adverse effect in terms of performance?

Thanks in advance!