A closer look....

[campsawyer]

Peter, I understand your concern for the vehicle movement and on a straight comparison of vehicle/foot speed you are correct. But I look at the movement not being based all on speed. I believe that the reduction in speed also models more fog of war of movement to compensate for the ability to see and know the position of the enemy. Given a double blind system, like you have created, increased speed makes sense, but given the base rules this reduction is one balance for the increased knowledge. As a second point, I also believe that the reduction helps to balance get a better simultaneous action effect in the game. By forcing them to slow, this will allow better chances for enemy actions to have an effect on them. As pointed out is some early AAR's by others it seems that vehicles now have a better chance to charge off the board than they did before.
So I am not trying to dissuade you complaint about it, as you are correct a on a comparisons of actual speeds, but I believe that the modeling for movement not only for speed, but to accommodate other factors in the game.