I couldn't have been happier with my stay at Kurt & Morgan's place. I stayed there a long weekend and I ended up liking it more and more each day. I really feel like AirBnBs rise and fall with how much the hosts care about making it a welcome space, and that was definitely the case here. It just felt like they put a lot of thought into everything; the bed was comfortable, the place was decorated well, everything worked like it was supposed to, and their welcome sheet had all sorts of helpful tips. Kurt & Morgan are friendly but also give you your space, so it felt very private. The wifi and TV both worked well while I was there, and the location was convenient to downtown. I was very satisfied with my stay---I would highly recommend you give it a shot if you're looking for a place to stay in Nashville.
Sidenote for road cyclists: I came to Nashville to do some biking and this place is really well placed for that---it's a quick drive to the Natchez Trace parkway, which is excellent cycling, and the trailhead for the Cumberland river trails is about 3 miles away, so you have plenty of options. The private enclosed fence made me feel pretty comfortable with my bike (and the neighborhood seemed safe to me anyway).