Just talked to the staff of PP service center in Hong Kong.
They confirmed that all Nautilus bracelets are changed to pins.
The reasons being numerous incidents of broken screw heads.
They said that the screw is glued to the link to avoid loosening, thus it requires skill to gently unscrew the screw. If it is unscrewed with force, the screw head may break.
I had my bracelet (with pins) adjusted at the PP service center, and with no mark "added" to the link in my bare eyes.
But I still prefer bracelet with screws, as it seems to represent a higher degree of micro-engineering and be more compatible with fine watches.
This message has been edited by joenghenry on 2012-09-14 22:58:10