I did it once with Cherry Coke and another time with Dr. Pepper. They came out great, I spritzed them as well with Dr. Pepper and some added spices. I haven't tried Jeffs Rub before with this kind of injection, but I bet they come out good.
I tried the Coca-cola injection on 2 butts this weekend. I normally do not do any injection, but I tried the coke injection on these. I have to say, I couldn't taste any difference at all, subtle or not. By the way, the pulled pork, after I added SoFlaQuers finishing sauce, was still delicious, so I was not disappointed.