In another thread someone mentioned the port size on the BLX Pro Open. They certainly look bigger than some of our other frames. The spin potential of the BPO is also HUGE. Tonight my wife and I took her brand new BPO out for its first hit. It's strung with VS Touch/Focus Hex 18 at 58/54. She gave me a few minutes to play with it and the spin was mind blowing! The relatively low weight provides ample head speed but even then the arc of the ball under the influence of the spin generated was absolutely stunning. Far beyond other "light" frames I've hit with. Precision was also top notch. Question: have studies been conducted on the role of port size and spin? I've hit with O Port frames and while the spin was equally impressive the feel wasn't as solid imo. And the Babolat woofer system seems spin friendly but not as precise as this frame. Question 2: what other Wilson frames use the same port system/size as the BLX Pro Open?