[Stuart]

It's swings and roundabouts.. These have the advantage that you don't need to find a spare USB charger, and then a socket to stick it in. They also have the advantage that you don't lose a socket when charging a USB device. But, the USB chargers are cheaper and easier to install.

I've got a couple of sockets to replace, and need more in the house anyway. Although I need to add enough that I'm thinking of getting an electrician in.