I chose 50J for a SIN-LON flight recently, which I am sure you know are overnight. I have to say I would not choose this seat again.

1) There is light leakage from the curtain which passengers rarely fully re-close when going to and from the forward bathrooms
2) There is also quite a strong airflow there which is exacerbated by the curtain being open
3) People inevitably sway into you as they pass, which on a flight where all you want to do is sleep is not what you want.
4) There is a wardrobe immediately to the left of the seat across the aisle, used for coats and (on my flight at least) crew baggage. The wardrobe is quite low and quite deep, the consequence of which is the accessing crew-member’s posterior intrudes into your personal space.
5) Obviously there are no window bins. I knew this, but I had forgotten quite how convenient they are.

For future night flights I would recommend a window seat which is tucked away.