I have spent three nights at this hotel with a friend in November 2011. I guess I enjoyed pretty much everything about this place.
1) Reception was very helpful and friendly (even during midnight check-in :))
2) The room was great - perfect temperature control, equipped with all the facilities you might need (and plenty of wall-sockets!! which was important for charging all the gadgets overnight :)), with very comfortable beds and excellent sound proof. Even the standard room is spacious. It was very clean and was kept that way by the cleaning staff during the whole period of our stay.
3) I found the location to be great as it's very close to the metro (5 min walking) but it's located on not a busy street, so it was very quiet and you can enjoy the tardy pace of life :) But those who travel to St.Petersburg for the first time should keep in mind it's not a walking distance to major historical sights of the city, so you'll have to use metro pretty much each time you go sightseeing.
4) Breakfast was not included but we had a chance to have a lunch in the hotel's restaurant. The food quality excellent but just a bit overpriced, in my opinion.
5) It was great value for money (it was November, so I'm not sure how it works in summer time when the season is high).

I would definitely recommend this hotel to anyone traveling to St.Petersburg.

P.S. Things I'd add in the hotel - tea sets in the rooms and a ramp at the entrance for the wheeled suitcases :)

Olympic Garden is on the way from airport to the city centre. It is close to metro line, so it's quite easy connect to the rest of the city. Hotel is relatively new and has comfortable rooms.

i reserved cruise tour from Helsinki to st.peter by st.peter line cruise and spent 1 night in Sokos Hotel Olympia Garden in July 2011 i reserved every thing from (Nordic Ferry Center agency )
the city was great and the room in the hotel was clean , beautifully designed , the food was too much and wonderful only 1 problem it was a Little far from the main attractions and very far from the port , the transportations was bad even the private bus service was bad and the drivers don't understand English .

This hotel is mid-rated among 4 stars hotels. The rooms are decorated beautifully with classic furniture and equipped very well with almost every things expected. Air conditioning was not good enough in the hot weather of St. Petersburg summer.
Housekeeping services was not perfect and may be oblivious to complete their jobs everyday. The Reception was warm and welcoming but the restaurant staff were slow and unhappy. The hotel's restaurant was not excellent but it was good enough specially its breakfast. The hotel lobby was simple and not very big but there was good place in front of hotel to sit and relax.