I own the 2254 SMP with the 1120 calibre movement (fantastic watch - why did it get discontinued...).
I am aware that the Chronometre grade of the ETA 2892 uses "better" components than the Elabore grade (Glucydur gilt balance wheel to name one) and that Omega modify the movement (winding assembly) to create the 1120.
I have two questions:
Does decoration to the movement improve the operation/efficiency of the movement or is it purely asthetic?
Secondly, does Omega only modify the ETA 2892's winding efficiency or are there other modifications to the base movement?