Doug,
I would get a ride on each of the boats and then decide which one you like/can get the best deal on. To me, there seems to be very little performance difference between them. I think each boat has its advantages and conditions it excels in.
AHPC and the Viper have been great for F16 in the pan handle. There are 5 new Vipers within easy driving distance of local regattas. Also, AHPC's support of the Alter Cup will give F16 a lot of publicity and bring 10+ new boats to the US.