I enjoyed this sequel, but it definitely wasn't as strong as the first book.  I felt there were pacing issues, and I felt like I was waiting for something to happen for most of the book.
That isn't to say that I didn't thoroughly enjoy it, I love this series and the characters, it was hard not to be engaged.
I just was hoping for a bit more, considering how strong and well developed the first book was.
I did like the inclusion of more mythology, this was definently took more of a turn away from science and leaned more into the fantasy aspect, but it still worked really well. 
I know this is only a duology but I would read another book in the series, I feel like there is still more to explore and I just really love the world that Kalynn Bayron has created. 

Definitely read this, especially if you enjoyed the first book.