i am probably wrong and i am sure pro alloy will correct me on this but here goes, as far as i can see all you are paying for with the pro alloy is the styling and quality of finish with the welding etc, my mates have both and i have radtec, the pro alloy stuff is much nicer and has a better quality finish and overall looks a better product, where the radtec is not as nice, looks or finish, but to me , i coulnt give a monkeys, the difference is minimal in performance, as far as i can see the extra 80quid or whatever it is for the pro alloy is for the finish etc, so reallyyou decide of you want the performance and the bling its pro alloy or if you just want the performance get the radtec and save yourself the cash, both worth the money, you decide what you want