I saw this -
http://www.wgt.com/forums/p/166617/1128542.aspx
I too have now played a couple of Legend tier tournament rounds, at Merion and Bethpage, with the 250 credits
TaylorMade Lethal Balls (L7+)
instead of the 450 credits
Nike 20XI-X Balls (L71+)
I usually play.
At 250 credits a sleeve I highly recommend giving the TaylorMade ball a try.
It's quite possible I have bought my last sleeve of Nike balls. LOL!