Skyward is definitely the better book.
The plot for Starsight meanders quite a bit and I felt some segments just stretching my belief a bit too much even accounting for sci-fi creativity. A girl and a ship hiding behind a hologram undetected though the security systems of advanced station with multiple aliens for multiple weeks...seriously? And Spensa convincing the Delver to leave ranks at par with "kiss saves hero" type cringe worthy endings.
Loved the cliffhanger where Spends steps into unknown and setting the scene for the next book.
Overall a weaker book, both in plot and content.