I personally do not recommend chocolates or carmel flavors in a ViVi Nova, it does not give a warm enough vape to give you the right flavor profile. Switch to a top coil carto/clearomizer after steeping and you will get much better taste from those juices. Do not forget to shake them well before using them. My personal recommendation is to shake enough to get small bubbles forming in the bottle, you cannot over shake a juice, but you most definitely can under shake one.
again these are my personal opinions, others may not agree, just how I do it.
From my experience, I would have to disagree. I have a peanut butter cup flavor from another vendor and it tasted great in a nova. Moved it to a CE4... awful. Like, I can't even vape it out of the CE4. I also have Dracula's Desire in a nova and it tastes pretty amazing. Obviously different devices and juices work differently for everyone. Just thought I would share my thoughts.