APOD
54
I have owned the 39mm in the past and currently have the Up/Down version....
The dial colors and details are very similar, except of course for the obvious, Roman vs Sticks, power reserve which I find useful.
To me, the main difference really is the size, ratio, and wearability. I find the 41mm a better-proportioned watch and also has a better balance on the wrist. I find the 39mm to feel a bit top-heavy since the diameter to thickness ratio is not as balanced. Also depending on your wrist size, the 39mm can look a bit small.
Either version is a winner, it all depends on your preference.