I strongly recommend Katy's place. The space is clean, comfortable, and interesting. It has everything you need. Katy was a great host; she gave us a lot of information about places to go during our trip.
The location is also very good. It's a quiet residential area, but there are still bars and restaurants within walking distance. There are also other cool places nearby in East Nashville, and it's not too far to drive or uber to downtown.
There are metal stairs up to the apartment that can be a little scary (it was raining during our stay and they were a little slippery), so this may not be the best choice for people with limited mobility.