So far reviews are not super-encouraging. How are their triple rooms? And is it easy to get a taxi that goes by metre from this hotel?
Taxis by the meter should be fine but you can get a room rate with airport transfers included. If you are thinking of staying here for a longer visit to Bangkok I would strongly advise you to stay in Bangkok itself. This is a functional stop over hotel for one night only.
Get an answer from The Cottage Suvarnabhumi staff and past guests.