Years ago, I signed up to have these books delivered to me as they were published. I guess I have all of the published ones - about 14 or 15 now.
The series is good, considering it's source. It is a great way for evangelicals to recognize the beauty of the early Church writings. I think at times by the selection of texts that the series minimizes some of the more "catholic" aspects of the writings, but not in a major way.
I use them as a reference when I'm studying a section of Scripture. I look it up in the series and first see what some of the Fathers had to say about it. Even though I've read a great deal of the Fathers, it still amazes me every time I read their interpretations of the Scriptures - our modern interpretations are so barren!