Be different and go for a supersprint 
. IMO it sounds much better than the milltek, costs more though 
http://www.youtube.com/watch?v=Vgo6779sS3g 
Don't go for a Supersprint, its borderline "popgoes your head droney" and the qaulity is so so @ best, speaking from personal experince, you would expect a £3500 full system to stop breaking its welds and having hiossy fits, not immpressed to say the least.
And they called both systems i bought LTW RACE
You'd think it was a one off on the CSL but the same thing happened on the E60 m5 and that was just a x pipe and backbox, also they take ages to reply back (eurostyling UK)
It sounds louder than a milltek but better
i think it depends if your a chav or not
( im part chav !)
The reason it sounds better is because it has alot of backpressure which actually starts to tear the backbox open !
stick to Milltek, i wish i did. great customer service and awesome product .
Millteks exhausts are OEM quite when doddling and trawling but open the throttle and its like the heavens open !
where as in my experince the Supersprint systems are LOUD AS FUDGE all the time near redline you will honestly go deaf and if you do trackdays YOU will get booted off if you have a full system
I've had 5 different aftermarket exhaust systems on 5 different cars, Milltek were the first that asked i take them for a test drive and check for any problems, then after they checked, they checked again.
there are alot of tuners willing to take money upfront and give you a product but no service once you off the forecourt !, you know you've found a great tuner when they offer great customer service.
I think Redrobin has said that before and i can't emphasise that enough.
