when i had my rac mb's i had rifle flighted 6.5, these shafts are all frequency matched so you'll get a consistant ball flight. i received my new rac tp irons about a month ago fitted with the new blue colored True Temper Tour Concept, these by far are the best shafts ive ever had fitted in my irons. i am not sure if theyre available to the public though? i also liked the rifle project x shafts, problem is with those are they keep the ball flight down which is a good thing for me to control trajectory, but i think most people are looking for a higher ball flight. all my club shafts in my new bag are sst pured, i havent seen a difference at all beyween a shaft that hasnt been pured, that is of couse you make sure whoever is doing your re-shafting is a quilified clubmaker. i have seen to often real "hack" jobs in which make the shaft work against the golfer.