with multiple bends and no real way to secure that hose to keep from rubbing. In stock setups and in the case you mention about silicone intake hoses, the hoses are well supported and don't get rubbed or bent. OEMs take care for Routing Quality Assurance. In the case or our engines, when a rubber hose is used, it has a formed shape to help keep it in place. In this case the hard line means no Routing Quality issues. That is the way I looked at it.