I've read the Mistborn trilogy. Summation: great conceptual "toy world" [1] worldbuilding, terrible flat cardboard characters (not to mention endless stupid infiltration of the nobility in endless stupid ball scenes in which the protagonist, who grew up a member of the slave caste, spends way too much time thinking about endless stupid dresses--er, I might have had an allergic reaction), and then...without being spoilery, I will just say that the ending was a horrible disappointment that could have been fixed in about 100 words but wasn't. Book 1 was all right, I nearly bailed on book 2, and only nagging got me to read book 3 and I kind of wish I hadn't. I don't know what you'd think of the trilogy, but if you get to book 2 and feel like bailing, you probably should.

[1] Basically, a world that works on a very small number of principles that the story then goes on to explore/enumerate, rather than one that exhibits the kind of exponential complexity you might hope to find in a more "realistic" world. I don't mind this style of worldbuilding, but I suspect it's an acquired taste.