As a seminarian, I have to say that I have found these texts invaluable. I own the set. And since it is merely translations of the fathers, not commentary, it is indeed Orthodox. Well, to be honest, there is a brief introductory section on each of the fathers that you can skip over - but the texts themselves are fine. A caveat however - these translations are old. The English is a bit archaic and unwieldy. However they are excellent.