CHRISTMAS CAROLS are in a sense enjoyable for their melodies, their sense of hope for the future, their warmth of expression, their "sympatico" "gemuetlichkeit" aura, and their familiarity, good if well-performed and scorned if poorly performed or too often performed Nowadays, there's music and entertainment everywhere, available in so many formats and venues that one is not starved for lack of options. Records, audio and video, complement the options, often in far better performance standards than current live performers and productions. Live performance is often more memorable and interactive, certainly more than "canned" performances.

When I was in school, we sang a great many medieval carols and motets, and they remain my favorites, followed by Appalachian and Elizabethan folk melodies, then traditional carols from all over the world. Some sound good with choir and orchestra, but the medieval carols were almost always unaccompanied and when well sung (like Anonymous 4) have a linear character that floats in the air. When you sing them, the group can breathe is such a way that it appears that no one takes a breath at all.

Some of these songs already have traditional harmonies. The ancient song
Nowel Syng We Bothe Al and Som is one such and Anonymous 4 do it with clarity and grace. On the other hand, the arrangement of Shepherd's Star (better known as Brightest and Best) sounded to me inappropriate to the song and its southern Appalachian sources.

I absolutely prefer the simple, unadorned carols. Coming from a Polish family, I learned the Polish carols very early. For me, carols are the expression of the common people about Christmas. You might know that "Infant Lowly" is a translation of a Polish carol. I sing in a country gospel group and for Christmas I select for solos carols like "Lift your torches, Jeanette Isabella" and "O Come Little Children."

I like the comment of Michael Meltzer above. But in general, with a few exceptions such as the Messiah, I am most drawn to the unadorned choral work.

I happily listen to the Anonymous Four and music like theirs for hours. I also love Bach's Christmas Oratorio, and grand holiday music. All that timpani & brass and glorious choral singing. Why should I have to choose?

I don't know... I do like the sound of the Mormon Tabernacle Choir or the old Ormandy/Philadelphia Christmas albums from the 60s and 70s. The sound of these women leaves me a little cold. They're no doubt talented at certain things but give me a big, lush choir any day.

Oh, I much prefer unadorned Christmas music! Have been filled to the blowholes with bombastic stuff. I see no reason to make Stille Nacht sound as though it's being performed by three football fields worth of megachurch choirs.Small and simple is best.

There is such a thing as musical intelligence and the answer to your question lies in the application thereof, with appropriate discretion. Form will then follow content.
There are carols like "Joy to the World" that beg for large forces plus trumpets, drums, bells and whistles. There are carols like "Coventry Carol" that are quite the opposite. There are many that are judgment calls, which will stand or fall on the skill and good taste of the arranger as his or her choice is executed.
I complain all year about how you select pieces in transcription. It's the same story, content dictates what works and what doesn't. Good taste must apply, case by case. There is no general rule that can be applied across the board.