One of the very best I have heard. People may not fully appreciate how difficult it is to perform a relatively simple piece so well. Without the complexity, there is nothing to mask the mistakes, but there are none to be heard here. And as you say, everything is so clear and the words are well enunciated, I'll just add that the tempo and rubato are also very well done. The counter-melody in the tenors during the "merry, merry, merry, merry Christmas" part is great, it's not always/very rarely heard distinctly, but here it is very clear; a fantastic performance.
