Personally I think there's a lot to be said about keeping the dwell time of gasses to the bolt carrier group the same as the original design to keep the timing of events the same.
A rifle length gas tube on a 20" barrel, middy 16", and carbine 14.5" all have the gas port the same distance from the barrel to keep the dwell time the same, though they run different gas pressures due to the location of the gas port to the chamber.
I think it's interesting that the 20" with the least gas pressure runs the lightest spring with the heaviest buffer weight, and is of the original design; yet some manufacturers will run a longer dwell time with a higher gas pressure with a lighter buffer with an enlarged gas port.