In my experience, faxing is a waste of time. I don't think they really pay attention to requests until you are physically there checking in. Last year at AKL, we meticulously researched choices and faxed our request to be on the Arusha savannah, on the trail near the pool and Boma (can't remember the name). We were paying for a savannah view. Well, we got there and checked in in the early afternoon. I mentioned at check in that we had faxed requests. We were assigned a room on the Sunset Savannah, on the complete opposite side of the resort from the pool. Nothing that we had requested. The room was OK, but I called the front desk and asked if we could be switched to the Arusha savannah. No problem, we were told. We ended up getting a room that matched our original request.
Moral of the story - I won't fax anymore. I will just politely request what we want at check in. Either we get it, or we don't.