The Deluxe Garden is the lowest class of room at CN. Next is the Deluxe Ocean and next is the Deluxe Beachfront. All of these rooms are exactly the same except for the view. The "Run of the House" you get with the Secret Rendezvous means whatever room is available at the time you go. It could be any of these rooms….or even a suite!
We have stayed in both the beachfront and gardenview rooms and there is not any difference at all in the room itself. Since the beachfront rooms don't actually look directly at the beach, I'd say just book gardenview. The whole resort is very close to the beach. We now always just book gardenview and we love it and save some money.