Atlantia seemed interesting. I started it thinking that it would be about mermaids and sirens. I was right about sirens. There seem to be a slight implication that they could be different take on mermaids but I didn't see it if that was the case.
The premise was lovely. I liked the description and the world Condie tried to build. After a while, her writing came off very bland. I thought I would care about the main character, but I really didn't. She made all the other side characters more interesting than Rio. The lore in Atlantic was intriguing, I wanted to know more. However, Condie took the old info dump route.
Condie's ability may have improved since Matched, however I still don't care for any of the characters she creates. I won't be continuing with the series.