hardtimes,
I can only tell you this, mine never leak when I am looking for a leak.
I do prime systems, dry sump externally with a drill and can see 50 psi on gauge.
I can run it on the dyno for a day, nothing.
If I put it into the car and wait one week, I get oil samples on the ground.
I have come to the conclusion that a car must leak, no matter what.
The Burtz seal works well, no doubt. All work well when installed correctly.
It is just a matter of time.
If you wanted a clean garage floor, start with a BMW.
John