The ARC choir one is excellent. One of my reference tracks is from one of their Blur Rider Trio CDs (harp, steel and guts) - Death have no Mercy in this Land. Particularly the harmonica which is very clean and pure. I play this a lot when I attended the RMAF and each year there were usually two or three rooms where the harmonica part was almost indistinguishable from someone playing in the room.
The only K2 I have is their release of Cantate Domino, which is excellent, but I don't have any other versions to compare it with.
I'll have to take a look at that Mapleshade recording, is it the "Blur" Rider Trio or did you hit the "r" instead of the "e" key? I do it all the time myself

I also have FIM's K2 Cantate Domino (translation: Can't play Dominoes :^) and it's a very nice recording. I have several others as well and all have been uniformly excellent.
Thanks for the tip on the Mapleshade.
Best Regards,
TerryO