Its not a pressure thing...obviously a -6 braided hose will take whatever pressure that a fuel pump will deliver.

However, long runs of hose are susceptable to damage from normal conditions more so than a metal tube. Also, even though the braid is on the hose, the hose does deteriorate similar to a normal, exposed hose. Some say that the resistance to flow is greater for a hose compared to a tube but in a street application, the difference in flow is not an issue.

As I see it, the three main reasons to run a much steel tube as possible and use hose for the vibration links are:
(1) the tube is more impervious to road damage and can be clamped in a secure fashion more easily, (2) the tube appearance is much better than a run of hose, and, most
important, (3) the cost of a roll of -6 braided hose is 6X the cost of the equivalent length of steel tube.