Everything went well for my two-week stay. Coyoacan is a good alternative to staying deeper in the city. I used the Viveros metro stop, and that line heads straight downtown to Hidalgo station, which is next to the Alameda.
Hosts Monica and Hilda were very gracious and helpful.
The apartment itself is comfortable and appointed with modern fixtures. The little kitchen helps with costs, but there are plenty of great places to eat, approximately 10 minutes walk into town. The central market has excellent prices on sit-down or take-home food.
I'd happily recommend staying here, but if you don't live by US dollars, watch the exchange rate. My stay was somewhat expensive in Canadian dollars, after the exchange rate, the BNB fees, etc. Otherwise, a perfect place to stay. Did I mention the huge Viveros park nearby? Great place to stroll and relax.