So, I guess the 2 12v vs 2 6v argument boils down to this analogy:
You have a 100 gal fuel tank, but can only get 50 gallons of it out safely without damaging the tank to the point where you can only get 95 back in, OR you have a 75 gal tank that you can get 70 gallons out of without damage to the tank and can refill to 75 gallons over and over.
How close is this? :B
Lyle