I have recently had the opportunity to examine one of the liturgies in use by the Western Rite Orthodox and must admit to no little surprise. Let me begin with some simple factual observations.
To begin with, the liturgy includes with it a traditional Gregorian chant setting, the Missa de Angelis. In terms of order, the liturgy follows the basic shape of Western (Roman) Rite in general, with a few noteworthy changes: a Preparation of the Gifts before the liturgy, the Asperges seems to be intended for every celebration, an optional Litany from the Gelasian Sacramentary which may be used in place of the Kyrie, the sermon precedes the optional Dismissal of the Catechumens, followed by the Creed (appropriately sans filioque), and the prayers of the faithful in the form of the Prayers of Supplication of St Martin. In the Liturgy of the Eucharist, the altar is prepared accompanied by congregational singing of the hymn “Let all mortal flesh keep silence.” The Anaphora seems to be as expected, followed by Ecce and Domine non sum dignus, and then a lengthy didactic congregational prayer “I believe, O Lord, and I confess….” During communion comes an invariable sung Psalm 34. After the blessing and dismissal follows the seasonal anthem of Our Lady, familiar to all Western Christians, and the liturgy closes with what appear to be congregational recitations of the Anglican General Thanksgiving (from the daily office) and four traditional prayers, another Kyrie, and the Gloria Patri and another final dismissal.
What is most striking in this liturgy is that it is presented in a modern English idiom that is formal and worshipful. All in all, I found it to be a reverent and very workable liturgy, accessible and accurate. It is truly a fine piece of work. The Russian Orthodox Church Outside Russia, whose liturgy this is, is to be commended.
This liturgy may be found at this site.