The food at Blossom is really excellent, and the service was pretty good. I really enjoyed the Black-eyed Pea Cake appetizer, it was the best of the things we ordered. The Seitan Medallions were also excellent.
There were a couple things that kept them from getting a 10 from me. First, the dessert was good, but not great. I ordered the Chocolate Ganache Torte. The ganache itself was perfect, but the cake underneath it was too dry. It came with a scoop of chocolate ice cream, but the ice cream was mostly ice crystals. It tasted good but the texture was completely wrong.
Second, they pulled the old "would you like sparkling or flat water" trick, which seems to be a New York thing. No, I do not want a $7 bottle of water, I want some tap water, and keep it coming. The "keeping it coming" thing is the third flaw, which is that our server only filled our water glasses when asked.
In another city, Blossom would be the best vegan restaurant by far, but in Manhattan if you're looking for a gourmet vegan meal I'd recommend Counter or Candle 79 over Blossom.