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!