I received the clay version of these shoes last week. I wear an 8.5 in tennis shoes.
The 8.5 did not fit and I returned them and received size 9s. The 9s seem to fit very well. I definitely recommend a half-size increase.
I cannot tell you how they play as I haven't worn them on court. I will wear these exclusively on clay courts and it will be a while until I am able to try them out.