1. The performance of Williams. I will be interested in the battle between Nico Rosberg and Kazuki Nakajima in addition to the battle with Red Bull and Honda.
2. Toro Rosso. With the performance of Vettel in recent week and the apparent advantage that exists with the Ferrari engine, I will be curious to see the what kind of performance Toro Rosso will have on a long power circuit like Spa; not to mention that their chassis is essentially designed by the great aerodynamicist and race car designer, Adrian Newey.
3. Speed differential. As mentioned above, there is a growing difference in engine performance as the engine freeze continues. I think it will be interesting to see the speed trap numbers at a circuit like Spa and in the future, Monza.