This has now become the oldest recording on the list, and without updated interpretations of these masses being available, remains an easy choice. The discussion below is from decades ago (as I write this new paragraph in 2020), and so obviously dated in its references, but does continue to summarize well enough....
These are both highly compelling works. In fact, this is the fourth recording of the Missa De plus en plus and third recording of the Missa Fors seulement released in the past year (1997). They fit together as a program partly by virtue of their relative virtuosity in comparison to Ockeghem's other masses.
The performances are both excellent. With the Missa De plus en plus, the competition is substantial, and this work has catapulted from being unrecorded to being Ockeghem's best-served on disc. Although perhaps lacking the pure virtuosity of some ensembles, the present performers have a great deal to offer. The rendition is very clear & lucid in texture without over-emphasizing the upper lines. It also offers the most compelling phrasing, although the various performances become closer on this point. Of course it exhibits the fine articulation and attention to detail characteristic of this ensemble. In the end what really sets this performance apart is the straight-forward and coherent delivery, lacking in artifice or pretension.
The Missa Fors seulement is perhaps an even better performance, accomplishing all of the above, plus adding a masterful pace and control of harmonic momentum. It packs a tremendous punch, and is certainly preferable in its lucidity to the other recordings of this work from the past year.
Todd M. McComb Updated: 8 January 2020