I've got 5 gallons of this going right now. I took the JAOM recipe and removed the oranges, cinnamon, and clove. I added 10lbs of frozen blueberries and two vanilla beans (sliced open and scraped, everything into the carboy). Everything else I kept the same.
It's bubbling along nicely next to the 5 gallons of JAOM and 5 gallons of Joes Quick Grape I made in the same evening.
Though I did have an emergency early on: the blueberries floated to the top of the mixture and I guess the CO2 being released kept pushing them up and up until they were almost touching the airlock. So I had to drain off maybe a quart of liquid to bring the blueberries down. They never creeped back up again. I suspect right now the blueberries are probably taking up a gallon or more of the space in the carboy, so I'm not going to get anywhere near 5 gallons out of that carboy.