The 12south guest house is an amazing place to stay! It really does look exactly like the photos provided of it. Tons of info is given in a booklet in the guest house, and everything is set up very practically.
The location is great, being just a quick walk to 12south and short drive to either belmont university area, hillsboro village, the gulch and downtown.
I would stay at the guest house every time i visit Nashville! Highly recommended.