If you love the "great" works of Tallis, those performed by Chapelle du Roi (on Signum CDs) could hardly be bettered. It is often difficult to sort out the lyrics and melodies of choral music recorded in a resonant space, but the engineers on Signum did it with their Tallis series, and the Chapelle du Roi know this music inside-out.
I do think these versions of the Missa Salve intemerata and Spem in alium by Oxford Camerata might have been equally satsfying had their engineer conquered the resonance of All Hallows Church.
In the Spem in alium, the verse, and even the melodic line, dissolve as the music soars -- then saturates the ears . Modest hifi systems may also reveal rolloff during the Spem in alium because the sound on the Naxos seems compressed at high volume. And that's a pity, because the Oxford Camerata perform this piece so beautifully.
Having said all this, I would buy this disc for its passionate performances. The Oxford Camerata are at the top of their game, and that will be enough for most listeners. At the Naxos price, buy it without delay, but if you really love these works, get the Signum versions too.