I've heard many longtime clearo users say that when they finally tried a real carto that it was MUCH more flavorful. And w/o all the clearo hassles.
I've been using these-
Tanks - Mom and Pop Vapor Shop
They hold Very tightly, and are easily cleaned. I put a 14GA. plastic needle cap on my 30ml. juice bottle, and open the sidescrew, and squirt it full quickly- and I'm done for the day.
With the grommets, you can use an inexpensive small carto in the big 6ml tank, making it very compact.
TBH I think part of that is that some people use juices higher in PG and some like me use high vg juices.
IMO there isnt much of a difference between a ViVi Nova and a carto tank with high pg juices * I still think the carto tnk provides more flavor, just marginally so in this instance.
Ive noticed a DRASTIC difference in taste between a clearomizer (which a ViVi Nova essentially is with the added convenience of a tube tank) and a carto tank with high vg juices and I think thats due to wicking.