In Divine Favor: The Paladin, author Stefen Styrsky gives 20 pages of new mechanical content for this divine martial class. He starts with the Divine Aspect alternate class feature, which grants the Paladin a suit of powers based on the Domains of his deity. This new ability replaces the Divine Bond class feature. These powers are usually constant abilities, like bonus to skill checks and saving throws against certain attacks. Only “paladin-like” Domains get this treatment (Community, Glory, Good, Healing, Law, Nobility, Protection, Strength, Sun and War). The abilities granted are faithful to its theme, like Trusted Strike (Law Domain) which allows a 14th level paladin to use the average result of his damage rolls instead of rolling.
Divine Favor: The Paladin introduce rules for Stigmata, the famous holy wounds of Christ and his many Saints. Here they mean divine displeasure and are a very original and interesting way of penalizing a Paladin (and also of moving ahead through plot). The interesting bit is that Stigmata not only inflict penalties, but also small benefits. A very nice twist.
We have 5 new Archetypes: Heavenly Beacon, Holy Sword, Metropolitan, Questing Knight and Templar. Most of these are mechanical-based variants (like the Heavenly Beacon, which works as a support character, almost as a bard). The Metropolitan is one of the most original – an “urban” paladin. The Questing Knight’s directional powers are a little off for my tastes (I envisioned this type of character more as an oath-based hero). The Templar is a great archetype, based on the idea of sanctuary and protection while far from home.
Divine Favor: The Paladin introduces Vow of Abstinence, Poverty, Honesty and Servitude to the class. Each one increase the requirements of the Paladin’s Code of Conduct but adds new spells to his list. While a viable approach I would prefer a spell-less option, particularly due to the existence of cool archetypes that don’t cast spells and, therefore, can’t take these Vows.
Now let’s check feats. Divine Favor: The Paladin has strong feats like Divine Initiative (add your Charisma modifier to Initiative) but also excellent ideas like Enhanced Holy Symbol (use your magical weapon as a holy symbol and add its total enhancement bonus to channeling rolls). Many of these feats require that the Paladin adheres to his Code of Conduct or to a particular Vow to keep its benefits*.
The Paladin is another good hit (or should I say "smite evil"?) for the Divine Favor series, which Divine Aspect and Stigmata been its most original contents. I believe that the Vow part of the PDF deserved a more careful examination and should be more versatile than just extra spells, but that doesn't invalidate this product's good points (and, in fact, it does give you plenty of ideas).
*Potential errata here: the Enhanced Divine Bond feat requires Vow of Honor, but I can’t find such Vow anywhere in the PDF. Am I missing something?