Having looked at both in person I feel that the way you want to wear it / time of day also may play into the decision.
The blue seems to absolutely pop in sunlight but in shade and blue light it’s more muted / blue green in feel…… the grey seems to wash out dark silver in hard sunlight but in muted light or in the evening it gets more contrast and a darker grey color that I really like
Same session at AP house on the balcony, mid day…. Full sun and shade
I also agree that the blue wears / looks larger on wrist than the blue dial from what I can tell.
With my 7 inch wrist that’s really playing into my preference for the grey
..Explorer & Spring Diver - I’m just here for the photos..