I don't have the pleasure of owning that many "high end" watches, but most of the ones I have seen in photos seem to have the usual ruby pallet stones on the entry and exit sides of the pallet, plus a ruby bearing on the end of the pallet staff.
Taking a peek inside my Ulysse Nardin Marine Chronometer I see diamond end stones in the pallet and a diamond bearing on the pallet staff. Now I'm wondering how many other watch makers use diamonds instead of rubies. The watch dates from 1920, originally it would have been a pocket watch for use in marine applications and has been professionally converted to a wrist watch.
I can't see that using diamonds would affect the performance of the watch in terms of accuracy or longevity/reliability. Rubies are the second hardest gem so they are not going to wear out overnight.
Just curious to know if this was a common practice.
So.....who's got diamonds in their ticker?
UlysseNardin4_zpse4dbae57.jpg Photo by Itsawindup | Photobucket
UlysseNardin11_zps86feb193.jpg Photo by Itsawindup | Photobucket
UlysseNardin1_zps63dbcf4e.jpg Photo by Itsawindup | Photobucket