MKing..
The difference between a PSS boot and a CV boot on a car is the the CV boot on a car is spinning at 70mph, through temp extremes, road salt, road tar/oil and has to rotate and turn a the same time.A PSS bellows does not spin, rotate or turn & is stationary. It's also Kevlar reinforced something the rubber hose on a traditional stuffing box or a CV boot is not! Both systems, the PSS and the traditional stuffing box, are connected to the hull with a rubber hose so I don't get the argument at all. If anything I'd trust a hose reinforced with Kevlar over one without. According to Boat US one of the most common causes of sinking, when dealing with insurance claims, is a leaking or weeping stuffing box! PSS's don't leak....I have a friend who's boat was badly damaged because the packing nut on his stuffing box backed off when he put his boat in reverse to back into his slip. Two hours later the marina called.... Anything on a boat can fail and the traditional stuffing box is more prone to leaks than a PSS and both need to have the hoses replaced periodically. The PSS however will not ruin your shaft by wearing a groove in it...