Same music, same choir, different director, different sound

A corespondent writes:

You’ve probably already seen this full length concert of Westminster Cathedral and the Sistine Choir in Rome (at St Mary Major and also the same programme at the Sistine Chapel.

They jointly perform Tu Es Petrus and Sicut Cervus by Palestrina (dir. Martin Baker). The Sistine perform some Roman choral music (dir. Massimo Palombella), and Westminster perform a longer set of British choral music (Taverner, Byrd, Tallis, Howells, MacMillan, Mawby), dir. M Baker. The join forces again at the end for Credo from Missae Papae Marcelli dir by Palombella (and how good it is to see the shared faith of both choirs acknowledged in this way.

What is interesting is the difference in style (in the joint works) that Baker and Palombella get from the choirs – same composer, same joint choir, different style….I wondered what your thoughts were about that? It seemed in the Credo that the westminster boys were pushing the music along – Palombella has a tendency to drag the polyphony out for some reason. Whereas Baker keeps it lighter and cleaner. Would you agree?

If you were Palombella what steps could you take to bring the choir up to the same standard as Westminster?