Good tip! I generally prefer quiet myself! I always pour over trip advisor to see if anyone complains about noise!
If you go to SMA, I highly recommend my b&b - Antigua Capilla. They have a roof deck with an amazing sunset view, besides great rooms and good breakfasts. They are located a walk down into town, though. My asthma was triggered by all the pollution, dust, car exhaust, and we had to cab it back up to hotel, which was around 50pesos each time. Think that's around $2.50usd. While SMA is great, I would recommend staying more time in Guanajuato, which is a beautiful, energetic, musical town, also filled with great art and artists.
View from B&B
We are thinking Mexico City next, though I just read it's sinking!