My understanding of fluid dynamics, which is worth about a nickel, is that all of those systems would act and feel the same. It comes down to the area of the piston exerting a force on the fluid in relation to the area of the piston or pistons being acted upon. I don't believe the size or number of lines between the two make any difference as long as the lines are large enough that they don't offer any real restriction to flow, of course. I suppose the more lines you have the more opportunities for expansion which would affect feel and power. If you had steel braided lines or whatever the cool kids are running these days, I imagine that affect would be negligible.

I suspect the different line configurations may offer other benefits. For example, dual lines, one to each caliper, may act as a better heat sink to pull heat from the pads than the other configurations. And the other configurations are probably cheaper.

I will try to ask someone who actually has hydraulics knowledge tomorrow and come back to pass that knowledge off as my own.

 

The difference between different line layouts rationale is cost of manufacturing vs ease of service. I've always found the "race" layout (2 straight hoses, double banjo bolt at the MC) the easiest to bleed. Pressure works as stated in post #2. Maybe more line area means more area to flex (expand) but the main purpose of braided lines is to prevent the line wall expansion, so it's nothing to worry.

Heat "stays" withing the caliper- it does not travel up the line by a noticeable amount.

 

Did the caliper upgrade, in this case from a cbr954, along with a master from same. Originally had dual lines/double banjo with that setup. Switched to a single line at the master to a tee, then one line to each caliper. I did this purely for aesthetics. There was no discernible difference, that I could feel, between the two.

 

My expert says I was right. About the first part.