Only Sanderson I've read so far is "The Gathering Storm", the 12th (?) book in Robert Jordan's Wheel of Time series. It was a slow read, despite Sanderson having already begun wrapping up more threads than Jordan ever started. I'm working on the book after it now just b/c I want to see how it all ends, I kinda got tired of Jordan's writing around Book 8 and Sanderson hasn't particularly enhanced that.

The one good thing about Sanderson taking over the series is that I have a personal rule that I stop reading a series when there's more books in the series than letters in the author's name. With a co-author added, it means I get to finish the series. :-P