Hi
Stuck in Chicago ORD catching up on these messages.
I should have been more diplomatic about Robertson screws and drivers.  Yes
there are better modern ones, many different drivers available now for
power driving screws quickly.  But I grew up using Robertson drive screws
(unless we needed to match flat head screws on a repair).  Most bone screws
in surgery use a Robertson or an improved penta or hex type drive for
facial plates and screws, or for orthopedic work ( never even seen Phillips
type for surgery).
I absolutely agree that slot drive screws look nicer but that’s not what we
were talking about.  I also have a gazillion flat head drivers, since if it
doesn’t fit the slot perfectly, it’s not great (should be able to hold the
screw with the driver, so the margin for error of fit is very small).
  As for cam outs and marring the screw and the work, the quality of both
the driver and the screw are important.
When using flat heads on something where it will show, I prep by
predrilling the appropriately sized hole/countersink, then use a Robertson
type screw to seat everything, then take out the ugly modern screw  and use
the same size screw in a flat head (I always bought full boxes whenever I
was in country side small town hardware stores that still had a few boxes
in the inventory).  It takes longer, but I don’t like scars on the screw or
the work.
   Stanley used to make these great drill countersinks that would make
exactly prep’d holes.  These work great and last a long time.  I’ll find a
photo and post it somewhere to share.
Cheers from ORD
Claudio