The Ducky ones have engraved legends - difficult to see unless the angle of the light is right.
Vortex have conventional doubleshot legends, but there is a slight variation in consistency between the legends across key groups (e.g. alphas, modifiers, function keys).
Personally I prefer clearly defined legends, so I'd probably go for the Vortex ones, particular the blue and white (which you didn't link to, but the same style as the green). Also considering that this round of Vortex legends are much better than the last one.