Sarah and Jan's place is centrally located for a stay in Prague. The place is extremely close to the busiest tourist areas and restaurants, but tucked away so it is quiet. The architecture itself is beautiful, with a wonderful shared outdoor garden that we sadly were unable to use because of non-stop rain during our stay.
Some minor caveats are that several bathroom fixtures are loosely attached to the wall--the first time I placed something on the top bathroom shelf it slid right into the sink. The apartment is on the main floor with windows to a shared entrance and another to the shared garden so privacy was limited with sunlight. The refrigerator was also filled with water, I assume from melted ice, which cascaded out the front door when I first opened it -- it turned out it wasn't plugged in.