I'm planning to demo the Yonex vcore 97 310 also. I have the same 'problem' with the donnay p1. Currently playing with a slightly customized MG Rad mp. Love the racket but I'm missing some spin and pop on my serves. I'm hoping that the Vcore has the same 'whipping' feel, but performes better on the serve.
HEAD MG Radical MP w/ 2 grams lead @ 3 and 9; testing strings...