Has anyone heard of MAGNEX?

I like how it looks, but know nothing about it performance wise. Here's a picture and description

Magnex Cat back system - 3.5" round tailpipe

Magnex specify high grade 304 stainless steel for all back boxes and systems. All systems have been designed on the car using electronic digitisation guaranteeing a perfect fit every time.
Magnex develop each system to produce a powerful combination of increased performance, tuned exhaust note and drop dead gorgeous styling.
Magnex are trusted by Aston Martin, TVR, Jaguar, Lotus (and many more!) to build high performance precision crafted systems for some of the world's quickest and most desirable cars.

Can someone tell me if this is a good choice? If not, what do you guys recommend. I was going for the RSpeed at first and now I'm having second thoughts.