This is going to be a mini mini review because I don't have much to say about Steelheart, and to be honest I'm just sad about not liking it.
Steelheart didn't feel like a Sanderson book to me at all. I'm not entirely sure why. Possibly the real world setting? Maybe because Sanderson's writing style seems to have adapted somewhat to a different audience. The Mistborn books and The Stormlight Archive are very much adult fantasy, whereas Steelheart is 100% YA.
I didn't care for any of the characters. The main guy, whose name escapes me, was awful. I wasn't sure if Sanderson was going down the austism route or not with this character, but if he was then he did an awful job of it. And then there's an awful romance filled with instalove and just awful and awkward scenes. I hated it.