The Mercure is a great hotel for business travelers. The staff all make a great effort to make you feel at home. The standard of English spoken is very good. Check in, check out, bar, breakfast and concierge services are all as good as one would expect. Efficient and friendly.
The rooms are all uniform, I have stayed in several and all were the same. All offer very good space (I have a standard double each time). The bed is very comfortable, the linen is comfortable, there are additional cushions to go with the pillows.
The bathroom is a semi-wet room with a big shower. There is no bath.
I have never once managed to make the AC or heat operate in the rooms. This is OK as the rooms are usually OK temperature and if they get too hot you can open the windows OK
All the usual stuff you would expect is provided in the room, including a kettle and bottled water. You can get an iron and ironing board sent to the room. They offer wake up calls and free newspaper
The breakfast is a good effort and includes champagne. It is Russia, after all...
Meals in the hotel can be taken in the Town House which offers formal dining of a good standard or you can get a range of burgers, salads and so forth in the bar. The bar food is really good. I recommend the Black Russian burger.