The Aeronaut's Windlass - Jim Butcher

The Aeronaut's Windlass is Jim Butcher's steampunk fantasy world. When the surface world is covered with thick mists and hostile creatures, humanity lives in spires and grows its food in vats. Energy crystals power the airships and weapons, and a select few can manipulate their energy without the aid of technology.

The book is a quick, action-packed, fun read. Also, one of the protagonists is a cat.

The Aeronaut's Windlass doesn't have quite as much social or ethical depth as I would like -- it felt fairly similar to the Codex Alera in those regards -- but it was an enjoyable read nonetheless.