Winter bounty definitely can turns games around in the Control Nature deck there are decks that revolves around healing and has a good win rate and Winter bounty shines in those. The imp is very good but also sometimes it is a curse more than a blessing but still one of the best cards released. Orfeo and Kadmos havent seen them used much but I would guess if they were used in the correct decks they would do great. Maybe the only drawback for them is that they need some expensive decks to perform better.