I used to do this route weekly, with a mix of economy and business and I thought that business wasn't worth it then - even though that was with the old (bigger) seats!
Now I definitely wouldn't pay (either miles or cash) anything extra to fly in CE, the only exception being if you don't have lounge access. If you'd like the lounge and have tonnes of miles then go for it. Otherwise, save your miles for something that's better value.