Excellent location: 7 minutes to Nevsky prospect by foot, the same to metro station, 10 minutes to Moscow railway station. All points of interest are pretty close (by foot or 2-3 bus stops at most): Hermitage Museum, Palace Square, Kazan Cathedral, Church of the Savior on Blood, Dostoyevsky Museum.
P.S. Pay attention to bathroom photos, please. We didn't make renovation in bathroom.