I hadn't encountered this one before.

It seems to me like it'll essentially be approval voting with the ability to give half a point of approval. There will be no distinction between 'Excellent' and 'Good'. What are the chances that two parties would make it up to 'good' median rating in an election, anyway? Maybe that's just the present-day US, but I have a hard time seeing people being that happy with politics.

But if they are, then there's suddenly no distinction between 'fair' and 'poor'. It's like since I don't like either of them I'm not allowed an opinion between them. I'll take Nixon over Hitler, please!