An adventure series that benefits from its great premise and good world building, but is otherwise mostly at a "serviceable" level of story telling. First off, the idea behind the series is a personal favorite: super-powers have entered the world in standard comic book fashion, but the people who exhibit powers all become criminally insane. The main characters exist in the aftermath of that event, and are baseline humans who use careful planning, guile, cunning, and technology to fight against the super-powered villains that dominate the world. I really like the idea; it's a theme that's been knocking around in my head ever since the original X-Com, and it's something that's popped into my head basically every time I see an X-Man movie. I've always thought that the humans and defense contractors dealing with the X-men were in a much more interesting situation than the X-men themselves. It's also a power structure that's produced some of my favorite games, e.g. Sang-Froid (where you are a flimsy, easily tired lumberjack fighting against were-wolves in the Canadian forest) and any number of other mystical monster hunter settings where baseline humans have to fight, research, and exploit the weaknesses of creatures that are inherently more powerful than them. So, if nothing else I love the premise.
The world building is also good, and as with the Mistborn series, Sanderson creates a world that poses interesting questions. In the Mistborn series the problem was that the answers to those questions were dumb, but here the answers are better. Besides the great premise, this quality world building is the other main strength and focus of the novels. These stories (again like the Mistborn's) can be thought of as world-detective stories, where the main concern of the novel is discovering how different facets of the world work. Characters, plot, dialog, etc. are all secondary to this process. So, typical questions in the Reckoners would be things like "what power explains the effect this super is exhibiting?", "what is this super's weakness?", "where does this new power combination or expression come from and how does it inter-relate with the super's psychology?". There are other and more involved questions that come later, but that would be spoiling things. :D The story spends much of its time on these questions and on fitting together various pieces as characters try to deduce how the powers of their world work. And the climax of the story is usually the Reckoners resolving these world mysteries rather than resolving more typical questions of plot or character. The plot does move along, but it always moves in tandem with discoveries about how the world works. I mostly enjoyed these mysteries and thinking about them; I felt like the author gave the reader enough information that they could usually resolve things ahead of time, which I like. Hmmm, what else. The first book is the most straightforward and compelling, the second book partially loses its way as it moves to a new setting and newer characters and less immediate plots, and the third book makes a comeback and has a surprisingly good ending. Along the way they hit any number of super hero tropes, and visit a city of steel, of water, and of salt. Oh, and they even made a mediocre board game out of series! As so often happens, though the books ruin the other media. In the board game the artwork for the characters is all wrong, which basically makes the game unplayable.