In general: the location of this hotel was easy to find and very central. It is close to metro station, Hermitage, Nyevsky Prospect and many other major points of interest. Arriving at Herzen House, we were greeted by Irina who locked our luggage in a storage room for safekeeping until our room was ready and gave us introductory tips for a short stroll and lunch. Upon our return, our (superior) room was ready (Despite initially booking a comfort room, having read the tips here at tripadvisor we requested an upgrade for a superior via e-mail. The hotel staff were so nice to offer it to us free of charge). Irina also booked a cab for our return journey to train station and gave us a wake up call about six in the morning.
Room: It was clean, practically designed and contained a pair of robes, slippers and a safe for our valuables. Bathroom was especially good with proper water pressure and heat, which is a treat given the poor infrastructure in St. Petersburg. Beds were comfortable and as a pair of heavy sleepers we weren't disturbed by anything throughout the two nights we stayed there, despite the fact that our window was looking towards the street. TV didn't contain much international channels but we didn't spend much time in the room anyways. The free wi-fi worked properly.
Minus points: A sharp smell of garlic welcomes you into the building. Although it is the unofficial smell of Russian cities in general, it is not particularly nice to experience it at the entrance.There was also an empty minibar in the room which didn't work very well. When we ordered beers from the reception after a very long and tiring day of walking around the city, we have been given a couple of lukewarm bottles from a cabinet in the corridor and minibar didn't do much to cool them even after an hour. Also the building's lift didn't work on the morning of our departure so we had to carry our luggage four floors down. And finally, the hotel offers the guests free tea, coffee, water and biscuits in the breakfast room all day long. It's a nice touch but this service did not seem to be maintained very well. Biscuits were far from being fresh and tasted quite bad. When we wanted to get a couple of glasses of water from the fountain before going to bed, two nights in a row there was no glass.
Final verdict: You can count on the safety, cleanliness, basic services and location of Herzen House but must not expect more than that - which is quite OK in St. Petersburg where hotels are rarely what they claim to be and presumably they are distributed stars in exchange for personal friends one makes in bureaucracy.
