The customer service has been fantastic and my orders have arrived expeditiously. I add the product to water with lemon flavor and Stevia to make a caffeinated beverage in the morning in place of coffee. I have not noticed a bitter aftertaste. I am a daily coffee drinker generally, and found the Liquid Caffeine gave me the same wake-up call that my normal beverage does. On mornings when I exercise, sometimes I will add Liquid Caffeine to my water, lemon and sweetener following my cup of coffee and I find I have extra energy during my workout. I heartily recommend this product. I have noticed crystallization on the nozzle after repeated use, but it washes away easily with water and does not seem to affect the taste.