In some respects, a Game of Thrones graphic novel is a strange thing - I'm not surprised that one has been published - but it seems an awkward challenge to create a piece that adds to the story without just piggybacking on the already successful show and books.
Anyways - since this was the only volume available at the library and I'm already pretty family with both books and television, I could get away with diving into volume 3...
So the first obvious benefits of the comic medium is the chance to image Martin's world without the constraint of sets, actors, budgets etc - and this is probably the biggest draw of the graphic novel. I was great to see some of the characters re-imagined more closely to the visual descriptions from the books. Some of the relationships and dynamics seemed different to the show, such as Tyrion and Bronn being a little more standoff-ish, Tyrion appearing less humble than on the show, these differences served to keep the comic interesting.
It was also great to see some aspects of the books, that had been omitted from the show, displayed in the graphic novel - Ned's dreams for example - the comic medium certainly enhanced some aspects of the story that were harder to follow in the books.
There were some drawbacks I thought, Martin's dialogue slots brilliantly into any format, however I felt the narration was a bit stunted, shortened as it was for comic form, just occasionally I also felt the artwork fell flat, one panel in particular was filled entirely with Drogo's grimace making him look like a children's cartoon character. Overall however the art was great.
In summary certainly enough to encourage me to hunt down the rest of the series, it is hard to imagine anyone other than strong fans picking these up, although they do provide an easier read than the books, so recommended for fans of the show who want to extend their reading but aren't game enough for the tomes.