The removeable faceplate means very little, it only means that when you remove the faceplate you can plug your device in below where the bottom plate was removed - you can have many of these around the house - the intended convention is that the advanced face plate is used on the master socket and extensions have a basic socket - in reality - the guy from bt will use what will serve the purpose as he is being measured on performance - so if they do not have any of the basic face plates left - he will use what is to hand (they are the same but a tad more expesnsive).