... make the 5959 p still the "better" choice , for me.
You are asking whether German silver is more durable than steel but durability is not the question if you use German Silver.
You can treat German Silver with acids and give it a black look by doing so if you do not like the natural patina of German Silver.
This is also why the 5959 movement seems to have a back shine ( I have not seen a 5959 so far).
The 5959 is far more traditional than this 5370 and the calibre used for the 5959 is purpose built (to be the slimmest) and exclusive to ss chronos only.
This 5370 is certainly a great, exclusive, modern and very likeable Patek but at this price point I would go rather vintage.
Thank you for the very informative read.
Best
Moritz