Rich - A clarification.
Shaft seals are self adjusting by their nature so they will not need to be adjusted once installed. Once the collar goes on and is locked, it's not going anywhere. We've never had to perform any adjustment in 20 years.
PSS no longer sells seals that need burping. They all come with a 3' hose that is led above the waterline. I was initially disconcerted to have an open hose in my engine compartment, but quickly realized that if I simply led it straight up and attached it to the underside of the cockpit floor, there would be no problem. Of course, I could take the hose off requiring burping, which is ok too. Do it once when the boat goes in the water and that's it.
One advantage to a shaft seal - you can't lose your shaft! I saw it happen once and the boat nearly sunk at the dock. The owner had engine work done and the mechanic forgot to tighten the coupling bolts. Slid right out the stuffing box when the engine was put into reverse. The collar on a seal would have prevented that. Pretty far fetched, but true!
Sabre 38 "Victoria"