Birds of Paradise is great at what it does. A mana-producing flying creature that when paired with a Mother of Runes can protect your life total in the air. In a deck with equipment like Sword of Fire & Ice and multiple creatures with exalted, BoP can also be a small aerial threat. For pilots who run black, Birds of Paradise is key to having access to multiple sources of black mana. I really like a 4/1 split of Noble Hierarch / Birds of Paradise for GW versions and a 3/2 split for GWB.