I always fax the hotel attention room controllers 3-4 days before arrival and have always gotten my requests.
I start with a little personal information like snowbirds winging their way south, looking forward to staying at your beautiful hotel, etc. Then I ask for what I want maybe 2or 3 requests in order of preference. We'd like a room overlooking the lobby and if we could see the MK fireworks that would be great or we'd love to stay in the mansions section, no special section but would like to be on the ground floor that perhaps looks out on a garden area(we had standard), or one time we needed near the food court, first floor with connecting rooms and another close by.
I end with something like we will enjoy our stay wherever we are located but appreciate it if you could accomodate us.
We have faxed 4 times and always got our requests.