I think I assumed that "double flavor" was "extra flavor". I feel like a few could use a little kick, but mostly they are great. I looked at the website the other day for your UK vendor and they said all of their stock was "double flavor" so it made me wonder.
I think that the black cherry marshmallow is on the light side flavor-wise. Right now I am using my samplers in V4L cool carts. I just put my Organic Rootbeer Float sampler in a V4L 3.5 ml tank with a 1.5 ohm dual coil carto and it is KNOCKING MY SOCKS OFF with flavor. I can't wait to try the other juices in my tanks... only three months left until my V4L juices are gone and I can move on...
I have also noticed that if I go from vaping the V4L (which I believe are Dekang) juices to the VV juices that my palette is desensitized for a while and I have a hard time tasting the VV juices. If I start off on VV they are outstanding. It's like comparing aspartame to maple syrup.