Originally Posted by rocket
I'm not even sure if the string density was any different either... The K90 was the 1st frame with such open string pattern if I remember right.
It was different. Wilson released that limited edition in Japan because there was so much speculation on the Internet that Federer was not using a real nCode90 as many had pointed out that his racquet had only 4 crosses at the PWS while the retail nCode90 had 5. So they drilled the nCode90 with 4 crosses at the PWS, put Federer's signature on the side, and sold them as "Federer's racquet" in Japan for a lot of money. But they forgot to shorten the pallet to make it look more like Federer's actual racquet. Good way for Wilson to wring more money out of an aging product that would be replaced by the K90 in less than a year though.