The standout on any compilaton of Tallis choral music is "Spem In Alium", and listening to this performance some 26 years after it was recorded is instructive. On my Hi-Fi there are moments when this is almost painful to listen to, such are the effects of the distinctive acoustic of Merton College Chapel and/or the recording technique. When the soprano voices come in, there seems to be a resonance which over-emphasises their range and creates a ringing overtone. At first I thought that this was something to do with my Hi-Fi, and to be fair, not everyone notices it (my Wife thinks the recording is perfect). But I recently bought both the Magnificat recording and that by The Sixteen in order to compare, and they don't have the same problem.
Now this is a notoriously difficult piece to record, and the problem of conveying the feeling of a performance in a particular place was undoubtedly more dificult a quarter century ago. But it could be done; witness the sound on the second disc of this issue, recorded in Salle Parish Church in Norfolk. There are no unwanted resonances, the acoustic is spacious and open, the sound cooler and more analytical. So I conclude that Merton College Chapel plays too large a part in the sound of the first disc, while Salle Church is a model of discretion. Alternatively the recording engineer may have kept his mikes just too far from the singers; some older recordings made with a simple crossed pair had problems like this.
This is still a wonderful compilation, but time has passed and it's no longer the automatic choice if you want a Spem In Alium (and it is a miraculous piece of writing for voice - perhaps the most accomplished choral piece ever). I would rate the competing "Spems" as follows: in first place that by the group Magnificat; in second the recording by The Sixteen (not all Tallis, other period composers feature); in third place this version by The Tallis Scholars from the mid 1980s. If you don't fancy any of these there are another twenty or so more or less available.
But this compilation is more than just the "Spem" and, particularly for the second disc, it's still well worth having.