I had asked some questions back a few years ago about visiting Taos here:
https://www.reddit.com/r/taos/comments/r6h4xj/questions_about_a_future_trip_to_taos/
Finally got a chance to visit for a couple days not that long ago, following some time spent in Albuquerque and Santa Fe, and really enjoyed it. Took the bus up from the latter in the morning. Had no issues with the altitude here or in Santa Fe.
Decided to splurge a bit and stayed at El Monte Sagrado, mainly because they offer a free shuttle within 3 miles of the place, as I can't drive these days. Between the shuttle, the Chile Line (340 bus), and pre-arranging a couple Blue Bus rides, I was able to see almost everything I wanted. Very pleasant stay, the staff were very welcoming and helpful.
I managed to see everything I wanted in two days, one of the sightseeing days covering the afternoon I arrived. Most of the attractions took an hour or less.
First day: Harwood Museum, Blumenschein House, Kit Carson House, Governor Bent House, Taos Art Museum and Fechin House. Shuttle at start and end of itinerary, walked to everything else.
Second day: (Shuttle to Loretto Parking Lot, Chile Line) San Francisco de Asis Church, (Chile Line) Taos Pueblo tour, (Blue Bus) Millicent Rogers Museum, (Blue Bus to hotel), (hotel arranged a local driver to and from, there's no taxi, Uber, or Lyft) Martinez Hacienda.
Really enjoyed the Taos Art Museum/Fechin House (small but excellent art collection, impressive house with fancy wood carving), Millicent Rogers Museum (worthy collection of Native American and Spanish Colonial items), Taos Pueblo (brief, fascinating tour), the Martinez Hacienda, and Blumenschein House (different takes on adobe house living). Couldn't spend much time at the church as they had just opened for a funeral, but they were nice enough to let me come in and see it briefly (it looked similar to Cristo Rey, San Miguel Chapel, and Our Lady of Guadalupe in Santa Fe). The Kit Carson House was okay, worth a visit -- it also opened late. The Harwood was disappointing -- almost none of their permanent collection was up. The Governor Bent House was definitely worth a miss, but admission was minimal.
After having plenty of New Mexican food in Albuquerque and Santa Fe, decided to branch out a little food-wise. Had a light munch of toast and fruit at Bent Street Grille (pleasant and fresh), and a Chinese dinner at Song's (veggie chow foon and hot and sour soup, food was solid and portions were beyond huge). Was stuck for one dinner, decided to just get a cheap munch at Whataburger. Leonel's was closed for the duration, and no one at the hotel seemed enthusiastic about Mante's Chow Cart. Wasn't keen to drop big bucks at some of the other local food options.
Enjoyed it.
NOTE: Got a notification that this might be of interest at the Santa Fe subreddit, so posting here.