"In the industry, Federerís racket is generally considered the most challenging to handle, above all for the recreational set. Its 580-square-centimeter, or 90-square-inch, head is the smallest in use by a leading player today, although Aleksandr Dolgopolov and the rising star Grigor Dimitrov use the same model, but with a 93-square-inch head."
I don't think that's true. I'm almost positive that Dolgopolov uses a PS 6.0 95 under his paintjob, and I thought Dimitrov uses a Tour 90. Now maybe Wilson has a 93 sq. in. version of the Tour 90 that they give to the pros, but Dolgopolov at least, isn't using it. And if it actually exists, why don't they just sell it to the public?
They would sell tons of them!