DTangstrom,
Most folks see a gain about like you would with an EZ, very similiar product as well. Customers tell us they seem to have more bottom end torque with the VA than an EZ too. The MPG you get will directly relate to the right foot, ie when you get a new toy you're gonna use it and play some so until the "new" wears off you won't see the total gain that it can provide.
Mark @ DPPI