The reviews highlight Koi's extensive beverage menu, especially its bubble teas which are praised for their quality, variety, and refreshing flavors. The staff are generally friendly and efficient, contributing to a positive experience. However, there are negative mentions about slow service, hygiene concerns including a hair in a drink, and rude staff behavior. Location and service times vary, with some noting limited seating and early closing times. Overall, Koi's drinks are well-loved, but service issues and hygiene complaints have impacted customer satisfaction.