For the money, I think the Meridian is better than Poliarnye Zori having stayed at both in both cheap rooms and business class rooms. It is in the very center of town, whereas Poliarnye Zori is about a Km South of the center. The rooms are cleaner, the bathrooms are nicer, the lighting is better. The prices are exactly the same as Poliarnye Zori, (between 1100 rubles and 4500 rubles, any travel site charging more is ripping you off) so they are clearly in competition with one another, but the Meridian has done more renovations and has more pleasant amenities and manages to transcend the Soviet feel that most big downtown hotels have in Russia. The desk staff is more pleasant at Meridian (they weren't terrible at Poliarnye Zori, but they weren't always friendly).

Cons? The elevators are tiny. The cheapest rooms have bathrooms that you share with your neighbor (although the cleanliness of the bathrooms and the rooms more than made up for this inconvenience in my mind... more