We stayed 2 weeks with two rooms at Hotel Cosmos in September/October in one of the superior rooms (floor 24) and was very satisfied overall. The room was clean with LCD TV, mini fridge, full size shower/bath. Fast Wi-Fi, although one room was much better in terms of connection than the other (side by side rooms).
The lobby area has a great selection of restaurants/cafes and we had dinner here every night over these two weeks, the food was great, a great selection and reasonable prices. There is a 24 hour pharmacy as well as currency exchange. Lots of souvenir shops with a pretty good assortment of items.
The hotel has very good security with staff posted at the door and scanners you must pass through when entering, as well as staff that check room cards before you may access the elevators. You are right across from VDNKh which is a great place to spend time relaxing or visiting pavilions, the space museum, and other attractions.
VDNKh metro station is a 5 - 10 min walk from the hotel. I would not hesitate to stay here again, and hope to - I already miss the hotel and Moscow.