As I've delved into the recent Aria 1.5 and GCPO releases, I've gone back and re-recorded this arrangement of the hymn tune Christe Sanctorum. My configuration in this one is 75% Garritan:
GPO4 hauptwerk as a foundation at low volume, sometimes adding the Scharf
GCPO stops, several of them, combinations switched on and off via midi (like using pistons)
Two organ SFZs, for specific sounds not yet in GCPO: a diapason celeste and a Skinner-esque string chorus.
Voices are also SFZ - a men and boys choir from Korg. (a very specific sound I am looking for)
I've dropped away all other non-Garritan stops I previously used, as GCPO has added clarity, depth and realism by several orders of magnitude. I particularly appreciate the 'blower motor' effect (ie, 'regulation'); listen for the round-edge attack - the late bloom - in the deep pedal.
I produce these in Finale, as I intend for this music to be performed live. Thus, these are not intended to be finished renditions, but more like a printer's proof - I think a real music organization (choristers, organist, and pipework) will be ever so much better, as will the congregational experience.
On my wish list for GCPO: a sample of one of American instrument maker E.M. Skinner's creations.