So - no takers for the round pin systems then !
The one consistent comment that does keep cropping up re BS1363 is it's size: as a '2 pin' plug (with inert or plastic earth pin) it is a bit large, but then it's very size does make it easy to get hold of, when removing it from the socket.
Just as an aside, I have seen some pictures of 'BS1363' moulded plugs, on several manufacturers sites, which are NOT fused. I wonder what countries they are for ?
P.S. In reply to pauluk's query, I hail from the sunny, balmy and HOT (today, anyway) Midlands.