Definitely no SS on YVR-NRT. Unless you are a big person and prone to sliding down the angle flat seat, I have read a few quite favourable reviews that conclude it is not an issue. It seems like the soft product (food, service) is bloody awesome and the new'ish plane still so nice (with the much touted lower cabin altitude, higher humidity, and all that jazz) that by the end of the flight, the dated Neo seats should be just fine. I am booked on YVR-NRT in J in early 2017 so I will find out firsthand.