When it comes to single serve beverages taste is almost irrelevant. Packaging and marketing is everything. Arizona is proof that you could put urine in a attractive bottle and people will buy it.
As far as energy drinks go, you get used to the taste even start to like it.
If you are selling energy drinks to bars I think it’s better to have a red bull clone. When you order a mixed drink with energy drink you expect the red bull type flavor. On the c-store level it’s look and price.
Tastes are subjective one mans meat is another mans poison.