I also had the taste described as cherry jello as well as your calling it bubble gum. I think both fit.
I found that Big Red grew on me. I had three – one bottle and two fountain. I always prefer soda from a bottle. Cans and fountain are me last choices. But this did not seem to make a difference to Big Red. I found the sweetness, flavor, and coldness to be a perfect way to wash down great barbecue. And me a beer man talking about soda over beer with barbecue. What is this world coming to!?