It's not EXACTLY like red bull, but I was very impressed with how close it was to the actual drink. On a fresh cart (or freshly washed cart too), it even seems like it's got a carbonated fizz to it. I'm not a fan of the actual drink, but this flavor is awesome! It's been my all day vape for 3 weeks now, and I've got tons of juice I've stocked up on it.
If it was a blind taste test with no label though, I'd probably guess Redcow to be mixed berry flavor with a hint of cola.