These are my thoughts about the Oxford Classical Text edition of the Iliad and the two modern editions; mwh, please correct me where I’m wrong:
The biggest problem with the apparatus in the OCT edition (apart from a certain amount of inaccuracy) is that it reports many of the variant readings in the medieval manuscripts by “families” (represented by lower case letters), which are not really families of stematically related manuscripts (i.e., manuscripts that are demonstrably copied from or descended from a common source that is no longer extant) but rather groupings of manuscripts that had some resemblances on what must have been a somewhat cursory examination. So the grouping of manuscripts into “families” is not methodologically sound and it’s misleading. (The OCT does report readings of some of the individual manuscripts.)
The problem is that there are far too many medieval manuscripts of the Iliad (and the Odyssey) and far too much “contamination” among the manuscripts (copying from two or more manuscripts and selecting variants from them, instead of copying from a single manuscript and reproducing its errors) to conduct the detailed analysis that would be required to establish the lines of descent (a “stemma”), eliminating from consideration manuscripts clearly copied from other existing manuscripts, and to group the manuscripts in true, genetically related, families, in conformity with the “stemmatic method.”
That said, the OCT provides information (said to be not always accurate, as mwh mentioned) about ancient variant readings and atheteses (excisions) by ancient scholars reported in the scholia, variants reflected in the papyri known up the date of its original publication (3rd. ed. 1920), and variant readings found in the medieval manuscripts. It’s not always possible to identify exactly which manuscripts contain which readings from the apparatus, but to my mind that doesn’t matter as much with a tradition as replete as that of the Iliad – knowing the existence of the variants is more important than knowing their source.
So even though reporting variants by “families” is somewhat misleading, it’s not as big a problem as it might seem (at least that’s what I think). As I mentioned, while the apparatus of the OCT would not satisfy contemporary specialists working at the cutting edge of scholarship, who tend to look down on the OCT with contempt, the text is perfectly ok for reading the Iliad.
In the face of so many manuscripts, both West and van Thiel adopt a different approach. Instead of trying to shoehorn their texts into the stemmatic method – a hopeless task – they select a handful of older, more or less carefully produced manuscripts (such as Venetus A), and select variants eclectically (if that’s not a tautology) among them, reporting other variants from those manuscripts in the apparatus. They both use almost exactly the same manuscripts. Van Thiel’s apparatus is stripped down to the basic information in comparison to West. For readers like me who have no pretensions to scholarship, van Thiel’s apparatus is actually more helpful because it’s easier to see the variants as you read (and having the text in a single, compact volume is a pleasure, too), but you can find a lot of information in West, and I usually go to West when I’m interested in chasing down a fine point.
Again, the major difference between the two modern editions is:
–West attempts to produce a text that is close to what he thinks the original text of the Iliad that emerged in 7th century BCE Ionia would have been (although the diacritics are based on Hellenistic/Roman-era or even Byzantine editing, and the alphabet is the later Ionian alphabet, i.e., the alphabet that is used in ancient and modern Greek texts today, not the earlier alphabet in which the text would originally have been written).
–Van Thiel thinks that it’s impossible to replicate the original text and largely attempts to construct a text based on the “paradosis,” the tradition that has come down to us through the medieval manuscripts that goes back to one or more editions produced by scholars in the Hellenistic/Roman eras, sometime after the 4th c. BCE.
