What's the difference, if any, between the Head Graphite Pro, turquoise color made in the USA and that made in Austria? There are also two black versions, one made in the US and another made in Austria. The black versions are stiffer and heavier (heftier) than the turquoise versions. Is it true? I have a black (USA) version which has great control and stability and contemplating on trying a turquoise version made in Austria.