For the extra 40 bucks a pump, I am going to dedicate one to each 750 and the use my rule 2000 for the ski locker and bow ballast. They will take a little longer to fill but no worries. I just want to be able to fill a side for surfing as fast as I empty the other one. I may even plumb a valve into the vent line so I can fill one of my extra 400s on the seat.