Billybolt,
The three wire - one wire deal is a personal preference. When all is said and done they will work equally well. If you try to calculate the speed of electricity in a circuit, you get into an area where no mortal belongs.
I think the interesting thing is that a single wire unit can be run as a three wire at the owners discretion. (I hope) I sure hope Mr. Mad Electrical doesn't spot this post...I'll be up a creek without a field winding.
Stuart
