Well, it's closer to Tolkien than to Pratchett, that's for sure
Although GRRM has a better sense of humour than Tolkien and there are a few laughs in there. Mostly, it's quite a serious series.
It's a bit different to Tolkien in that it's more closely based on Medieval history, particularly the Wars of the Roses. There are fantasy elements - magic, unusual creatures and races etc - but these are almost non-existent at the start of the series and only slowly emerge. There is heraldry and feasting and tourneys and battles and duels. The books are more adult than Tolkien. There is sex, there is violence (though never gratuitous, at least IMO). Major characters die. Not everything is laid out on a plate. A couple of storylines you have to think about before things become clear.
The books are based closely around the pursuit of power, who has it, who wants it, who doesn't want it but is suddenly given it, and what they do with that power when they have it. This theme is explored in-depth in the books.
There are some of the more colourful and interesting characters in all of fantasy, whose machinations and motivations are fascinating but not always obvious.
Is Martin better than Tolkien? Certainly he has more realistic and more interesting characters, and his books are much greyer. Good and Evil are harder to define as these aren't fairy tale characters. They're people, with all the flaws of real people. It's hard sometimes to know what 'side' you're supposed to be rooting for, and the true enemy in the books is elusive and rarely seen, at least to date. Martin isn't as good as Tolkien at languages or in mythology-building, but he's better at the more immediate history that precedes the series, a history that is only revealed slowly as the books continue their forwards-moving storyline.
In short, yes, it's fantastic and certainly the crowning achievement in Epic Fantasy since
Lord of the Rings itself. I recommend it
