- PBEM. (this is a big one, for such a long game that is AGOT)
- Based on Asmodee Digital previous records, they releasing all the expansions is a big IF. Terraforming Mars still only has the base game, and it has been out for a long time.
- The community.
- Close communication with developer/easier to implement changes and other features.
- You can play on your phone.
etc.
And since SnR is a non-profit site, I do hope and believe that FFG will leave it alone. They don't really have a reason to strike down on sites that has kept the AGOT interest up, which will benefit them for sales of the official version.