They have the ability to remote disconnect you without any visit. Some people might regard that as a disadvantage.
Personally, I think this control needs to be taken away from the suppliers and passed to an independant body which will require some suitable evidence and/or court order before allowing disconnection. I'm not very comfortable with the suppliers being able to control it themselves. There's also the issue of this control being broken into due to poor security - imagine if some school kid in Russia finds he can switch off the power to
10 million UK homes at the push of a button on his laptop.