The flavor is so watered down, the drink can taste like green dairy foam (especially the unsweetened version).
If you don't finish the drink within the next couple of minutes, the matcha green tea powder will separate and float on top of the milk. Unless you stir vigorously, the drink ends up tasting like milk.
Even if you ask for no syrup, the powder comes pre-sweetened with 24 grams of sugar for a tall, and 43 grams for a venti.