Hi,
I have no experience with the FP3. I tried both the Prince and their time trial FM1, and I was not too impressed by either one. They did not feel stiff enough, it gave me the impression that they were built more for comfort/leisure riding than for speed. Even the time trial bike was not that responsive, which is weird on a tt bike. Not a good feeling.
But then it's just my opinion and I'm not an expert - so I would recommend that you try it on a test ride before you decide.
Good luck!