"Prayer of Christians" was the quickly created response to the Pope Paul VI's revision to the Divine Office by "National Federation of Diocesan Liturgical Commission". It represents the spirit of the age of changing things quickly but not really knowing where everything was going. Because of that, this edition of the Divine Office has some very traditional elements mixed in with some wacky novelties. Just a couple of points and then we'll just look at the pictures.
-The Psalter is not infamous Grail version, but the same as the 1964 Roman Breviary which I reviewed (rebound) here. It is a translation of the Pius XII Psalter.
-The hymns part of each hour is called the "song". The Office of Readings begins with a sentence from scripture. I suspect this was done for ecumenical reasons.
-Finding the prayers for Sunday is difficult. To my eyes, I cannot see a way to tell which week in the Psalter you should be using, as you can in the 1975 Liturgy of the Hours by look at the Sunday you just celebrated.
-Some of the prayers and Collects are laughable. They are worse than the current (now defunct) ICEL versions.
-The antiphons aren't the same as the ones in the current version.
-The Scripture lessons in morning and evening prayer are different, or sometimes longer than the current edition.
-It is expected that Morning Prayer is the first prayer of the day, not the Office of Readings. "O Lord Open my Lips..." and Psalm 95 are placed at Morning Prayer.
Those are just some of the changes that came in this edition. I don't think this was, although I could be wrong, an obligatory version of the office. This was printed before the Latin Liturgia Horarum was complete, and so I believe most clerics were still praying the 1962 edition in some cut down and modified way. Once this came out many probably switched over to this right away though.
Here is a photo of the layout. It looks shabbily done. All black text.
The 1975 version text layout is a vast improvement in every way. Here is a comparison.
Artwork is what you would expect.
Here is a comparison of both editions. They are the same size. Prayer of Christians lacks the ugly "Chi Rho" symbol used in the 1975 Liturgy of the Hours. The cover has more texture, and the color is more mute than the newer one. It also doesn't seem nearly as cheap. However if you compare sometime like this to Breviaries that came out just ten years early you will notice immediately that they were cheaper. The first edition of the Liturgy of the Hours was worse in some ways. The modern printings are slightly better. I think that is representative of how they treated Liturgy in general at the time. It was to be for the common people and so they made it cheap. Cheap cheap cheap. Gratefully we are correcting that nowadays.
The binding. Sewn.
The canticles and other common cards are "ecumenical" translations and are promoted as such in the preface. Just look at the end of the Our Father.