PSS seal on a 43 Cabo last month during sea trials.
I have found that placement of the water injection hose is critical. In this case at WOT the pump pressure exceeded the spring pressure of the bellows. At loads under 90% the unit acted normally, only issuing a fine mist indicated by a line across the bilge and corroded motor mounts, generator etc.
The typical operator would have no clue unless he was in the machinery space at high cruise.
Perhaps the high speed units Mr. Hemming is using have better performance than what I am used to seeing. It certainly appears he has installed many with no issue.
Good luck with whatever road you choose. As with most things, a good installation will always improve your eventual satisfaction.