I think a lot of people find the idea of playing a half vampire interesting. The potential inner conflict with your darker nature, or the outer conflict with your parentage can really provide interesting moments at your table. Dhampir: Scions of the night provides this in spades.
The are a host of ways to customize your Dhampir. After giving you a fair bit of Flavor in the first 2 pages, you have a number of alternate racial traits to personalize your Dhampir. Some of the ones that really stand out to me are the variants on spell like abilities. While detect undead is somewhat useful (particularly if you are going with the Dhampir Vampire Hunter Trope), it can be a little lackluster. These alternate spell like abilities offer some very interesting additional options, and they all capture a piece of the lore that surrounds vampires in game. From animalistic form, which at high levels allows you to change into a bat or wolf, or draining touch, which gives you a taste of the power that vampires wield against life itself, you'll find something to suit your tastes here if you like vampires.
This product also offers a number of interesting character options. In particular the rogues Play Dead Talent seems like it could offer an interesting dynamic to a combat. Its a bit more flavorful and dramatic then a simple in combat feint to get in a sneak attack. Overall I'd say you can find a number of interesting options here for most any kind of Dhampir character.
It is also a very useful tool for DMs who want to include Dhampir NPCs. First and foremost it has several fleshed out and detailed Dhampir NPCs at the end, complete with backgrounds, tactics and plot hooks to bring them into your campaign. In addition all of those alternate racial features are laid out in tables that you can roll against randomly if you need to generate an NPC on the fly. There is also a random feature chart with everything from bite shaped birth marks, to pupils that disappear in the sun. There is lots to flesh out what sets your Dhampir apart in this table.
Overall I'd say its a very good product, and definitely brings that can't wait to play one of these feel to playing a Dhampir Character.
[5 of 5 Stars!]