I love Adrian Tchaikovsky’s books, but the Shadows of the Apt felt pretty slow to me. I’ve read through the first three books (I think) and I don’t remember much other than the setting being neat. Haven’t read Echoes of the Fall at all.
Highly recommend the Children of Time series, the third book in particular gets me sobbing every time. The Final Architecture was great too, and I enjoyed Cage of Souls.