My partner and I chose the Hotel Misión de los Angeles only because it was the only hotel that had availability during the busy holiday time. We spent four days at the hotel and enjoyed the extensive buffet breakfasts each morning. The grounds of the hotel are pleasant. It appears that most of the emphasis is placed on the exterior because the interior of the rooms are stark and bland (like many Mexican hotels). The rooms were lackluster with the typical Fred Flintstone bedrock beds. Rooms were clean, perhaps due to the ever hardworking cleaning staff who woke us up each morning trying to clean our room. This became quite a nuisance, especially on New Year's Day when we looked forward to sleeping in. Overall, the hotel was adequate (grossly overpriced) especially if you are seeking a more intimate, unique experience. I probably would look into a B&B or boutique hotel next time.
I would like to encourage folks to check out the following dining venues in Oaxaca:

Como Agua Pa' Chocolate (try the cornish hens in rose-petal sauce or the chiles en nogada!!!)

Danzantes- a beautiful restaurant
El Naranjo- increible

Stay away from the NY Times recommended "Temple"- a dining disaster!