First of all, skip any of those counterpoint books that push that Schenkeian drivel on you. Jeppesen's book is pure and straighforward- no baloney!
There are so many superior features to this book that it's difficult to choose what to mention, so I'll just begin with the fact that you do NOT get flooded with more examples than you can possibly make use of. Jeppesen gives you exactly what you need, and streamlines his information to that which will teach you the 16th century style. He begins with a solid background in the history of music theory since the Middle Ages, which helps to understand not only the technical tools the 16th century style, but also the aesthetic objectives. How he breaks down the building of the melodic lines and the combining of the parts is surprisingly complete, considering the small size of this book. The language is quite dense, though, so it will take a few reads to reap the most benefits from this book. But it's more than worth the extra time!
I highly recommend this book for anyone who wants to learn 16th century counterpoint, and not spend time going around in circles with a lot of self-serving verbiage.