I don't know the specific benifts in the UK. I do know how it works in the U.S. Northeast during the winter months and that's wonderful. Warm floor is always nice on the feet on a cold winter morning.
My friends had a steam type floor heating system in their home. The house was always warm in the winter, cool in the summer. They used natural gas for their system. Unlike the gas heated steam system, with an electric system you will not have to worry about leaks. Also heat rises, which makes a floor heating system less wasteful then a forced air system with ducts in the ceiling.