Back in October, the "Broadband Forum" had their annual "Broadband World Forum" event in Berlin.
As part of this, they added a "Broadband Access Summit" this year, with a lot of free talks on both G.Fast and NG-PON2. Why couldn't they do that when BBWF was being held in London???
Anyway, it seems that the slides from the presentations are now available for download, so you can get a flavour for where the state-of-the-art is in both of these technologies right now.
https://www.broadband-forum.org/what-s-happening/meetings-events-webinars/broadband-access-summitThere was one event in Berlin, and a repeat in Las Vegas a week later. Openreach presented at the first one, but not the second. I'm not sure how much overlaps there was between the two events.
There is a good "market update" presentation that is part of the "intro" slides.
Happy reading