In regards to taste, I love the Lime freeze flavor of these. I hate when energy drinks have that typical "energy drink" flavor and try to stick to the couple that are fruit flavored and that I know are good. The lime Rockstar tastes like a Sprite with a kick and I love how carbonated it is (I have a thing for super carbonated drinks). When it comes to caffeine, I have a very high tolerance and would need at least two of these to feel anything in regards to energy but I am also a breastfeeding mom so I limit my caffeine intake and one energy drink every couple days is sufficient for that. I mostly just hope that the placebo effect kicks in and my body thinks that this is giving me enough energy to last through the day. But as a drink in general, I do enjoy the lime freeze Rockstar.