Hi,
I spent ~24 hours in 40J to Fukuoka and back in April.
There's definitely a few extra inches compared to 40G. I didn't get a tape measure out but I compared the gap with that of EC on my way off the plane and to my eyes the gap is easily closer to EC size than it is to the standard economy distance.
To give you some idea, as a slim person I could fairly comfortably stand up in front of my seat facing the aisle with both feet side by side on the floor. This wasn't possible in front of the other seats.
The different angle of row 40 compared to row 39 didn't cause any problems with the alignment of the TV or table which still seemed absolutely fine to me.