A mono-white flying token generator with a small upkeep cost? This is pretty awesome in my books. Yeah, it has a upkeep cost of 1W, but it's an instant-speed token creator, so what else can you really ask for? White kind of hurts for good token generators. They either have to tap (Thraben Doomsayer), require some sort of counter/charge (Twilight Drover), or have some sort of weird restriction (Security Detail). Even the other token generators that don't have some sort of restriction aren't as good as this. Heliod, God of the Sun costs 4 for a 2/1, Pegasus Refuge makes you discard cards, and Mobilization costs 3 for a 1/1 groundwalker. I know that the upkeep cost may turn some off from the start, but I think it's pretty worth it.
Pros: Instant-speed token creation
Cons: Upkeep cost