The new CLANBOOK LASOMBRA offers wonderfully details- clan factions (including antitribu), Lasombra skepticism of origin legends, Chinese bloodlines, Embrace traditions, how the Occult rating relates to Obtenebration, and a better sense of Montano and Gratiano. It has many standard series features- MET statistics, character templates, merits and flaws, a discussion of clan disciplines, a sample pack (Lasombra computer hackers!), and noted Lasombra (less basic but more multicultural than the original).
It's also the first new CLANBOOK on the Sabbat. It emphasizes Humanity over Paths of Enlightenment but gives extensive treatment to the distinctively Lasombra Path of Night. (Other VtM books assign important Lasombra to the Path of Power and the Inner Voice- not even mentioned here, unfortunately.) It describes Path of Night variations (the Path isn't written out here so you must refer back to VtM's basic rules) and introduces Abyss Mysticism, a practice by which Lasombra merge with darkness.
An improvement in the new CLANBOOK: LASOMBRA is the emphasis on young Lasombra instead of elders, making the clan seem less cartoonishly pompous. It features Asian, African and Northern European Lasombra not the usual Spanish Lasombra. Rather than being traditionalistic, the Lasombra seem cut off from their own history because so many elders died during the Anarch Revolt.
A minor problem is that there's almost too much introduced for atmosphere and basic themes to fully develop and not enough follow-up on earlier material- characters like Medina and Lopez, for example. Also, the original CLANBOOK series was more interesting visually than the new one. The original LASOMBRA featured white type on (appropriately) black pages. (LIBELLUS SANGUINIS I's Lasombra chapter also does this in places.) Darkness oozed over the page from the pictures illustrating Obtenebration. The new CLANBOOK: LASOMBRA uses only conventional white pages and the art loses impact because of this.