If it were my money? Omega.
Why? Omega’s coaxial escapement movements are amazing. Check out YouTube, there is a great video about the METAS certification process fully cased Omega coaxial escapement watches go thru. COSC? Never heard of her! Omega’s brand heritage > Tudor’s. And while both watches are every inch tools watches the Omega would, I think, dress up better so is the more versatile between the two.
Full disclosure, I’m both an Omega and Tudor fanboy (wear the Omega SMP, the pre-coaxial Speedy, and the Tudor BB58). I don’t see a bad option here really.
So let us know what you get, and pics when you do!
Nice! I actually purchased the while dial version last December, only to return it after I realized the GMT had was perpetually wrong! It was always either half an hour behind or ahead of the main hands - but another way, the GMT hand never lined up "on the hour" when the main hand was on the hour. First time I'd ever seen that in a GMT movement.
I did ask the CW rep when will they have the green dial GMT with the "twin flag" logo rather than the Christopher Ward text. He said they would after existing stock is depleted and to look for new photos on the website when they do. As much as I like the white, that green dial is unique!