Hi Jack,
As others, I am sorry to hear about your trouble.
I have myself a Marine chronograph, the big sister of your Marine big date.
The purchase is relatively recent, so the data point may not speak for much.
Accuracy is not as good as yours (around +5 sec/day - but I wear it all the time). So far, I was lucky enough that the rotor works ok.
My watch right now, as I speak, is now almost fully wound, and the rotor seems to rotate ok in both directions. Possibly with slightly more resistance than not wound at all, however still rotates with gravity as I move the watch slowly in a vertical plane around a central horizontal axis, both clock- and counter-clockwise.
I'm no expert, but I guess the failure to wind automatically may be due to the shape of the rotor (e.g. friction agaisnt the saphire caseback?), or perhaps the link between the rotor and the barrel-winding mechanism. Regardless, it should be something fixeable by Breguet.
I'm concerned about this case, and can only hope that it will be resolved properly. My 5827 (BA) is one of my all-time favourites due to its elegance and mix of Breguet classic styling (very pretty hands and guilloché) with sporty/sturdy nature. So I would hope that it can work properly for as long as possible.
Best wishes and keep us informed.
Jon.