I'm with you on that Sheldon.
The SD scewdriver is the only screwdriver I will use on my oyster bracelets.
Most other screwdrivers are either less than 1.6mm or the edge is too thin.
These other screwdrivers will nearly always leave witness marks especially if you strike a stubborn screw.
Check out the contour of the SD screwdriver tip and you will see why this is THE tool to use.