I was thinking a shootout between the 450F and the 250F. Then a comparison with the 250 2T and 125 2T. Many potential buyers I talk to think "I'm a big guy, I need a 450" or "a 125 will be too slow for me". When the truth is that very few of us can ride even a 125 to it's potential. Think to Kurt Caselli in recent times (competing on a 125 in the desert), Shane Watts in the GNCC's, or Hannah overalling the combined 125/500 events.
I believe in the notion that over the course of the race, the 125 is fastest. There are times and sections when the bigger bikes will have an advantage but I think that over the course of a long hot event, the minibike rider would be fresher at the end. I'd also like to see the lap times to see if it is just a pro level phenomenon or if it is the same down throught e ranks.