Sam, I haven't tried Black & Blue yet. I do like Peach Green Tea though, and I have tried Crackberry, which I did not like. I'm going to try it in the Magma though. It was too sweet for me. Not candy sweet, but too much flavor. Same experience with Cherry Bomb - loved the first few vapes, then it was too much. Now I use it as a mixer, and it's great. I imagine that the blueberry might help balance the blackberry in B&B.
Try a small bottle! Worst case, you have something you can add a few drops of to PGT for variety.
Try a small bottle! Worst case, you have something you can add a few drops of to PGT for variety.