Love my 956P recently installed. Mine is mounted using 3 of the steel rod protruding down threw our top story composite shingles and locked in tight to our attic wood structural members.
Issue- When wind speeds exceed +/- 15 MPH, the play between the brass rod that's brazed to the bird underside which drops down onto the steel rod generates a clanking noise because of the gap. The clanking noise is transferred through the steel rods to the roof structural members and into the house. This is an issue.
Solution- A strong sealed bearing mechanism incorporated in the lower supporting steel rods with a male thread and female thread on each end combined with filling of the previously mention gap with silicone cauking.