On the Orpheus Ireland website an entire page is present, which is devoted to describing and comparing various choral learning aids.
Choralia and Choralplayer are very well described and reported:
In my view [Choralia] is the best source of choral learning files currently available. It (…) has a powerful built-in player that provides all the playing controls needed. Further, it employs Virtual Singer technology to simulate the words sung. It has a very large catalogue of works and is free to use.
Also, a very detailed description is provided, covering both the general characteristics of Choralia’s learning aids, and the specific use of Choralplayer (formerly Choralia mp3 player) as an additional tool available on top of Choralia’s mp3 files.
Many thanks to Tony Harpur for providing this valuable resource!