Fairmont is one of my regular hotel in Singapore but I dont stay there during the F1 as the room rates are normally higher than neighbouring hotels. May be if you get a room with a view of the track its worth it. Breakfast in a Singapore 5* hotel runs around $40-45 a person. Not really worth it, have breakfast somewhere else. By the way if you can spare a minute of form filling you can get free Wifi at the Fairmont by joining their Presedents Club
Last Year, Ferrari were at Pan Pacific and McClaren drivers were at the Conrad. Best place for driver spotting is Gate2.