About the first row of Y seats after the Eco Comfort zone.
I was on a 772 last week-end with 15F seat.
After comparing with other Y seats, I would say that you have a little bit more legroom than "normal" Y seats. But I think, if the seat upfront is reclined, you loose this advantage. I don't know about that because the eco comfort zone was quite empty and the purser offered me a Y+ seat as a frequent flyer. And I really enjoyed the extra legroom, for free!