The only thing that changed is that most carbon shafts are extremely light and ever since they came out, trad guys have been trying to figure out a way to make them work, first they said that they didn't need to be weighted, then they said that weedeater line etc. was the be all end all, then the latest fad is the high foc.. The testing I have seen and done proves only that a high foc carbon is better than a badly weighted one or an unweighted one. It is very easy to add one and one and come up with three, if that is what you wanted to come up with in the first place.