I stayed here for 2 weeks in a bussiness trip. The location is 5m away by taxi from the airport. Hotel has a shuttle bus every 30m from hotel to airport.
The facilities are modern and the room size is good. No sound at all coming from the airport, nice and quiet.
Complementary coffee/water/tea every day in the bedroom, nice touch. Very clean every day.
Be aware, no mini-bar in bedroom, only in reception you can find some drinks/snacks/amenities.
The restaurant has a good breakfast but limited options for dinner, in my case i optioned to go to the close Shopping Mall (Galeria Mokotow) to eat something (5m by taxy, 20m by foot).
The staff is excellent, very friendly and helpfull at all times. 5* on that.
If you want to go to city center you have the 175 bus across the street for 4,40zl, it takes 20m to get there, easy (by taxi arround 30zl-35zl).
You also have a small gym (bike, treadmill, eliptic, weights and a couple of other machines), enough to stretch the tired muscles.
You have free wifi in all hotel.
I highly recommend this hotel, just be aware that if you have a long stay (like i did) the dinner options are limited.