I have anecdotal evidence to back that up. If you look at the "Drivers you currently own:" thread, you'll note that I have 2 Turner 504 drivers in 11 degrees. The first was my gamer for three years, the most consistent driver I ever owned for distance and accuracy. The second I bought as Diamondtour was clearing them out so I would have a backup for the first. Shortly thereafter, the 1st one went dead and I lost 30 - 50 yards in distance (I can't see it, but there must be a crack or some structural issue) and the second, although better than the dead original, has never approached the good original.