I am partial to colored gold, but in this particular case (pun intended), platinum made total sense.
My preference for the Geneva Seal comes from the fact that it was created in 1886, is shared with other brands (my CdV and LUC bear it) and is awarded by an external office. The Patek Philippe Seal was created only recently, in 2009, and is awarded to Patek Philippe watches by... the brand itself!
Best, Emmanuel