But beware of the noise in the rooms overlooking the central place.
We arrived at the hotel without reservation and we were given first a small room at the top floor overlooking the street and the central place. It was very noisy and asked to be moved to a more quieter room. The staff was really helpfull and found us what we were looking for. I guess the move was possible as it was the low season and there were very few people in the hotel.
Beds were comfortable and bathroom, although slightly smaller than what one could expect for the price of the room (70 USD, which is expensive for the town).
We just had one night, so nothing really to complain about. We would maybe look for a smaller "boutique" hotel next time we go to san cristobal.
We would recommend this hotel to our friiend for sure.

You can't be any more central than this -on the Zocalo. Hotel is probably 3 star standard with price to match. They add taxes to the quoted price so a run of house room is about $78. My room was in the old centrral wing. It was huge with 20 foot beamed ceiling and a very large bathroom with separate shower/wc. As it was over the kitchen, it was hot and had no aircon or fan, but opening the windows onto the central courtyard let in some cooler air. However the dining area was below and setting up for breakfast made noise until about 11pm.
Not sure how the newer rooms in separate wing might be, but Expedia gives you run of house so you have no choice.
Eat all your meals out - it will be much cheaper and there are dozens of choices within a minutes walk. The cafe on the east side of the Zocalo is great for people watching and you can write your e-mails while having coffee.
A must is the trip to nearby Indian villages - really interesting. Take the tour offered by 'Alex & Raul' at the front entrance of the cathedral off the Zocalo every day at 9am (departs 9:15, returns 2:30; $25).

Pack your bags and head to Palenque and San Cristobal. Sunny days in the jungle at Palenque- we missed the three days of previous rain . There is great inexpensive food, lodging on the Zocola at Hotel Ciudad Central Historico (make early reservations), and an atmosphere of a Colonial City in San Cristobal. Our cab driver was playing Mozart when we arrived and we found very few US citizens. A guided trip - available each morning at 9:30 from the fountain (NE one block from the Zocolo)to the local villages is a good way to understand the mixture of catholocism and shamanism.

We returned again to Oaxaca, via the night bus, to our favorite Las Golondrinas. Oaxaca City is becoming more of a US destination and since we have visited two times, we probably will adventure to some new destination next time.

We stay there in June and it was a beatiful accomodation. It hadn't air conditioning, but chapas is quite cold so you probably will not need it as we didn't need it. The room are large and clean (maybe quite dark) and also the bed is king size. The staff is kind and they speak english. The breakfast is nice. The location is in the centre of the city.