Does great artwork count as "useful" in your book?
Serious, though, I myself am not going to run a campaign with these rules anytime soon, but I definitely think the book is a good buy (plus I had some money to spend anyway
There are a small number of new benefits and drawbacks that could be used in any campaign.
If you are just sticking to the standard noble house roleplay there isn't anything critical here. If you want to do another style of game (mercenary group, clans in the mountains of the moon, Dothraki, etc.)the Wildling tribe creation rules look like they would be more suitable (with adaptation) for the time being.
There are a lot of nice little campaign hooks and adventure ideas. These are North flavoured (I love the one where characters have to cross a frozen lake with Wights under the ice and an Other waiting for them on the ice), but any DM can re-work them into non-Wall encounters.