Location is very good, few mins walking from Central Line Marble Arch Station.
Apartment is nice, there is enough space. We were 4 adults and 3 kids and we were really comfortable.
The only weak point is that if you sleep in the room on the street side there is noise (bars and cars) that is quite annoying. Bring some sleep protection in case you have light sleep. The apartment and the building are very warm as heating goes through the walls.
Check-in operations very smooth, very clean conditions.