“But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed.” (Galatians 1:8)
I must preface this by saying I believe the NO is valid, and I attend and have attended it.
That being said, there is much in the New Rite, which, if not bad, is very, very unfortunate. I see a great deal lacking in a rite in which 13 genuflections are reduced to 2 (and many priests do not do that!), over 1000 orations to less than 400, and the removal of overtly Catholic-sounding prayers, mentioning saints, purgatory, Our Lady, etc.
If we as Catholics accepted this change without question, I do not think we would be doing our job as servants of Christ, and St. Robert Bellarmine points out we should correct even our superiors to prevent the spread of error. If Cardinals Bacci and Ottaviani (of Holy Office fame) were concerned (and, apparently, Padre Pio) than should we not be also be at least unsettled at the numerous and arguably unneccesary changes? No doctrines were further clarified, no teaching better expressed, and no abuses to be corrected. I am troubled that the NO seemed to be introduced for no better reason than modern practicality, which is not what Christianity is about.
Heretical? No. Valid? probably. Worrisome? Yes. I am 100% for full restoration of the old rites if for no other reason than to remove ambiguity from the intrinsic nature of the rite and restore clarity. Certain reforms are okay, and I have seen beautiful Anglican Old Rite Masses in old English. Beautiful! That I can see. But the NO as it stands lacks a certain richness, which, even if celebrated well, it will always lack. There is no subsitution for the fullness of Faith. Pace