Initially, Winter is not the most likeable character, especially from outside his head. This book gives us a good look at Icewing culture and how its rigid adherence to order and desperate clinging to old hatreds is leaving them behind. The concepts of friends and forgiveness are tough for Winter, and it's delightful to see his progress. Once again we got to see a dragon grow, learning what things he could/should do on his own and what things he needs to lean on his friends to accomplish. We see him making complicated and well thought-through decisions, and I'm looking forward to seeing what happens next.

My recommendation for reading order of the Wings of Fire (WoF) series:
WoF #1-5
WoF Legends - Darkstalker
WoF #6-14
WoF Legends - Dragonslayer (this could be read after book #5, but that would spoil a sweet surprise present in book #14)

The WoF books follow a five book plot arc (with each book covering the growth arc of one character). If book 1 doesn't work for you, consider starting with book 6 or 11 to get invested in the world. Each book adds to the complexity of culture and history in the world, so you may miss a little if you skip books, but the overall plot and story will work.