I do wonder what someone who has not read the books makes of it, particularly the multiple settings and huge cast of speaking characters. For me, though, it was like meeting old friends (although the definition of the term, friend, might need a little broadening for some of them).
Now I've seen the disks - I won't subscribe to Sky Atlantic - I have to say I'm impressed. Yes, the book and season are not in 100% agreement, but I can't think of anything further from the butchering one sometimes sees.
In the highly unlikely event that I bump into GRRM, I'll have to congratulate him not only on the books but also their adaptation to the "small" screen. I don't think I've ever seen Fantasy on the TV that so easily throws off its genre-ghetto shackles and instead looks like a particularly good example of history brought to life on the box. I don't think I experienced even the slightest temptation to genre-cringe** at anything (something all too common with just about every other example of TV Fantasy).
As for the opening credits: hidden info-dumping at its best. The theme music, which I didn't much care for when I first heard it last year, is a definite earworm.
** - I use this term because I know that some have found the sexposition (which I prefer to call info-humping) somewhat off-putting. While I was expecting far more screen time to be devoted to it, given the publicity during the season's run, it did veer towards cringe-making. However, the contents of these scenes was in no way genre specific; these sorts of scenes are present in many TV adaptations, whether of explicitly literary opuses or more mainstream, genre or cult books.