I mean, it's absurd. When I'm reading Sanderson I'm about ten times as alert as I usually am while reading fantasy, because I know that not only is a plot twist coming, but that it will be well set up with what would seem like some minor details. It happened in all of his books that I read. And still, time after time, he surprises me. When I finished reading Steelheart the twist was so darned elegant that I lay down my kindle and clapped respectfully when I read it, despite being alone in the room. Other authors may write as fast or (equally rarely) as smart, but not both.
It's really quite amazing. In Steelheart, I knew the twists were coming. I even vaguely knew what characters and plot points would be involved in said twists, and still I was unable to fully predict them.
Then with the Stormlight Archive, you have some characters popping between the worlds, and little hints of the crossover that are only apparent if you are paying attention (for example, you might notice a character using Rioting from Mistborn). And it all makes sense. It all fits. I legitimately don't understand how he can keep the entire Cosmere so consistent with so many tiny hints that are almost unnoticeable by the reader.