Magnaflow no doubt. Its exhaust parts sounds better than the other. It runs like a beast and it gives the car the best performance at all speeds.
The VCM is probably the most expensive option out there, but I love mine! Even without the corresponding tune (yet) I saw a 2 tenths improvement in ET in my M6 GXP. The quality, fit, and finess are top notch, and installation wasn't too tough.I have been looking at the vcm-performance OtrCai - looks great and is apparently better performing than others tested.
There is a thread on it here.
Do you research....... Other performance shops in Australia all declare the VCM intake for the G8 / VE from JHP is the best power & Dyno improvement with a perfect fit.The VCM is probably the most expensive option out there, but I love mine! Even without the corresponding tune (yet) I saw a 2 tenths improvement in ET in my M6 GXP. The quality, fit, and finess are top notch, and installation wasn't too tough.