I think it looks great as long as the photos are not depicting the correct hue. If they are then then Omega have gone down the Michael Korrs rabbit hole.
Would I buy one? I don't think so, and I certainly wouldn't trade one for my DD40.
Also, unless the Speedy Sedna commands a premium, you are moving into a different price bracket to the DD40, especially olive dial, and moving further away by the week.