Just depends on the gun, load, and shooter. I've seen both shoot excellent groups. I've had several 45's that would shoot with any 44 I've ever owned

The FA or the 5 shot 45's myself and other builders make are to allow you both to shoot hotter loads and the heavier longer bullets normally seen in the 454. You can keep the cylinder at standard length but it would be kind of a waste. For those reasons the 45 in the longer 5 shot cylinder will have even a larger edge. My thing with the 5 shot 45 is that if you go to that extent of work and cost, unless your recoil shy you might as well go to the 454 and then you can shoot both although I'm a proponent of cartridge specific cylinders in which case you could have both cylinders.