in my opinion the F3.0 Tour has a bigger sweetspot than the Biomimetic 300 Tour, and it is also higher up on the racquet face. I'm still not convinced that it has more power than the prior version but the F3.0 definitely has a livelier stringbed and is "snappier". The older box beam shape feels nicer and more traditional but both frames hit a heavy ball and are very stable given their static weight and beam width.
I believe and understand other people's experiences and their feeling that the F3.0 has a small sweetspot. From the stringing error made with my F3.0 i can say that it is not as friendly or forgiving if strung close to 60 lbs. Once I had my setup of 55/52 it played awesome - the sweetspot was larger and the stringbed less jarring.
If a large sweetspot is desired than I believe that a rounder headshape is better. An oval shaped frame is better for flat ball strikers and aggressive all court players who place a premium on control. My game is not well suited for a powerful frame so I tend to like the oval head shape. The new F3.0 is trying to find a middle ground which I think Dunlop acheived. They also fixed the need for adding lead to the upper hoop, though I still did.