The Orlando Consort have a great recording of Josquin motets that is one to a part.
A Sei Voci tends tends to use male singers and add a children's choir for e.g. masses/non-motets, which can sometimes sound a little muddy or sloppy, depending on how particular one is.
Likewise, in the past, the Tallis Scholars have been criticized for being too soprano-oriented, with two great a difference between male and female voices, and choosing surface beauty over scholarship. Their older Missa Pange Lingua recording has been specifically derided for this, and also some odd rhythm and tempo choices.
Both Ensemble Clément Janequin and A Sei Voci are much better in Missa Pange Lingua.
The Tallis' recent Malheur me bat recording, however, does not suffer from these problems, nor does really their recording of the L'Homme Arme Masses.
Some people will prefer A Sei Voci's more lively timbres for the Arme Masses, albeit with maybe less precision.
I forgot:
De Labyrintho, an italian group
Musica Symbolica (with Missa Gaudeamus)
and
Music for Ercole I d'Este (with Missa Hercules Dux Ferrariae)
Both very well reviewed. I only have the former, which is great, but their Hercules Dux Ferrariae was also rated by some as better than the Hilliard Ensemble's or Pomerium's.
