...As to which boards have the fastest bases? IME Bataleon TBT bases are the fastest. Not because of material but because of the camber+TBT. Almost no drag in the snow=straightline rocket.
I can attest to this.
Although I've only ridden a handful of boards, when I took my Lobster Jib Board out for the first time (also TBT) I couldn't believe the speed. Could be a coincidence, but it was a huge difference!