Dubai is not short of five-star hotels. With new ones opening all the time, some of the city's more established names face a different challenge: how do you keep standing out when you are no longer the latest hotel on the block? The twin towers of Grosvenor House, a Luxury Collection Hotel, Dubai, have been a big part of the city's Marina skyline for years. And there is something reassuring about the fact that the hotel does not seem to try to reinvent itself to compete with every new opening.