I just used the test balls I received.  All I can say is  ... are they legal?   The longest ball I have ever played.  I had a local pro Chris Repass and a club rep Scott Larson were shocked.  Repass was dumbfounded as I was hitting it 30-50 yards past him - I gave him one of the balls I had been hitting on 18 and he was within 10 yards of me.  Seriously long.   I didn't find the irons too much longer but they really held and I found them similar as other Pro V1x's.  I hope this ball becomes more than just a test.