Has anyone elaborated on the differences between the Byzantine and Syriac versions?
Yes. John D. Witvliet, "The Anaphora of St. James," which is one of the essays contained in Essays on Early Eastern Eucharistic Prayers, edited by Paul F. Bradshaw, which I highly reccommend. The essays contained therein are much more analytical and informative than the more general, and somewhat Liturgical Movement-biased commentary in The Eucharistic Liturgies, by the same editor and Maxwell Johnson, although that work also discusses the variation, although I could not say it "elaborates" on it.
It does however point out the interesting fact that the current Armenian Orthodox liturgy has an anaphora, named for St. Athanasius, that is a condensed version of the St. James liturgy with some elements of St. Basil, attached of course to a near-Byzantine Liturgy of the Catechumens and closing with the Last Gospel, John 1:1-14, as a result of the influence of the Eastern Orthodox and Roman Catholic churches on the Armenian.
If, however, want a point by point comparison of the textual variants, Witvliet's essay is what you want, in addition to also reading copies of the text itself.
Also, Essays on Early Eastern Eucharistic Prayers has similiar chapters on the other ancient Divine Liturgies of Eastern provenance, including St. Basil (there was or is a Syriac Orthodox St. Basil anaphora, although I've never seen a text for it, as well as an Armenian), St. Mark/St. Cyril (the Greek and Coptic variants), and St. John Chrysostom, as well as its Antiochene predecessor the Anaphora of the Twelve Apostles, and the Anaphora of Hippolytus.
These essays only go into detail on the Anaphorae, and not the Prothesis or Liturgy of the Catechumens, so if you are looking for information on that, you will want either the aforementioned Eucharistic Liturgies, which compares the whole rite, and as an added plus also covers the Western liturgical tradition (the Roman Canon, the Mozarabic Rite, et cetera), or alternately, the Oxford Handbook of Christian Worship, which is itself a collection of essays on the worship practices of all branches of Christendom. All three books I highly reccommend.
Also, there is a book entitled The Eucharistic Epiclesis, which I love, because it focuses on that part of the Anaphora that I think is the Holiest and also the most interesting to compare; this is by John H. McKenna, CM. This naturally features a detailed analysis of the Epiclesis from the St. James liturgy, although not so much of a comparison between the Syriac and Byzantine recensions. That work gets a bit more interesting when it comes to the complex dual-epiclesis structure of the Alexandrian liturgies (St. Mark, St. Cyril, and the Euchologion of St. Serapion of Thmuis, which His Eminence Metropolitan Seraphim of Piraeus recently celebrated), and also in its analysis of what we might call the distributed Epiclesis of the Roman Canon, and the controversy over when the Real Change happens, but is at its absolute most interesting when it provides us with a parallel comparison of the Epiclesis from the three Anaphorae of the East Syriac Rite (attributed to Sts. Addai and Mari, Theodore of Mopsuestia, and the unpleasant figure of Nestorius, although the liturgy attributed to him looks to me and to many scholars like an importation of St. Basil, a sort of generic Constantinopolitan liturgy renamed for the Assyrians' favorite Constantinopolitan bishop).
All of the above are available as e-books from iBooks and Amazon.com.
In the Syriac Orthodox Church, that portion of the liturgy is more or less standardized (we begin with Ho Monoges, and then there are the Scripture Lessons, the Qawmo, a series of linked bidding prayers or collects, and the Trisagion and Gospel, and of course the Creed, not in that precise order, but more or less; also I believe you can hear the clergy chanting the Prothesis behind the curtain immediately before the liturgy, at least I think this is what they are chanting, immediately following what I think is our Mattins; the schedule for St. Ephrems Cathedral in Burbank calls this period "Morning Prayer" and I like to arrive in time for it, but unlike with the liturgy, a translation is not put up on the monitor, and we use a lot of liturgical shortcuts, for example, in our Archdiocese we only use the Anaphora of St. Dionysius Bar Salibi, because it is the shortest, but to comply with the Rubric requiring the Anaphora of St. James to be used on certain occasions, the Institution Narrative and Epiklesis are from the latter liturgy).
