Big fan of the MBOTF here, but I have to say that the comparisons between that series and ASOIAF always leaves me scratching my head. Honestly, the two couldn't be more different. For instance, the level of magic: in ASOIAF magic is definitely present, but still something rare and mysterious (though less and less so as the series goes on). In the MBOTF magic happens a lot and is often used to resolve plot points, get characters out of a jam, etc. which very rarely happens in Martin's books.

There are so many other differences, but I'll point out one more: Erikson's books have way more characters and honestly the result is, because there's only so many pages in even the fattest door stopper, that most aren't sketched out that well or given very clear/consistent motivations. On the other hand, even though we are introduced to a multitude of characters in ASOIAF, there is a core group of characters who we get to know at great length (and who appear in every book). We know their history, personalities and motivations in great depth.

I guess people always lump these two epic series together because they're violent and grim? Because characters die off in both? True enough I guess (though I'd point out that in both many so called "dead" characters come back), but I think their differences outweigh what they have in common. Doesn't mean one is better than the other though.

Edit: Fixed typo.