There really is no reason to leave your cabana with all the comforts Disney provides you, but there is a little thing out your door called a private beach that may sway you.
There are two things about Cabana #1 that make it a bit different. The first is that is has a wooden walkway to the beach because it is handicap accessible. You can easily roll a beach wheelchair along the path and onto the beach.
The second is that you are right next to the family beach. You get to see how crowded it is and also watch the Disney security stop people from coming over to your beach. (nothing like being a bit snobby and wanting the commoners to remain on their side of the rope 😉 )
The beach is wonderful. There are enough chairs and umbrellas for each of the cabanas to have their own without invading each others space.
There are also stacks of float tubes and flat floats for everyone to have their own if they want. These are included in the price of the cabanas. Regularly this would run you a ~$10 rental per float.