I've never heard of the shape affecting anything - all I've heard is, go as big as you can afford, & you can fit in the space available. Better to have the pump running longer than having it kick on, kick off constantly - that's a pump killer.
I didn't think I'd get 5 years out of my well pump, but since I tripled the tank size, I'm on year 9 and the power draw seems to be about the same. Usually when the meter spins like hell that means failure is imminent. High draw to overcome worn components. The difference between my old pump and new pump in how fast the electric meter spins was huge.