This flat is charming and in a wonderful location. It is walkable from train station, but realize the authentic cobblestone streets are not big roller wheel luggage friendly. A taxi to the train station is inexpensive and a much better option, because when walking, Google maps takes you through inner malls rather than streets so it can be confusing.
Also, we found it was much better to exchange money in Old Town, rather than the rates at the train station or the machines in general. Enjoy your stay in enchanting Prague!