Ruby's dial is a bit more accurate, IMO.
The twin dots at 12 o'clock look a little too far apart on DSNs. They might be smaller diameter than the gens, so then getting them close enough to the hash marks on the dial forced them further apart? Also, it would appear the "L Swiss Made L" at 6 o'clock is a bit too small on DSNs.
Though this is based on looking at pics from panerai.com, which are notoriously inaccurate....