Here is my experience with the Vivi Nova V2.5: I have three of those tanks since I liked them so much. Then the trouble started. I used them on a GG Stealth and had numerous shorts, melting the mod's bottom spring and ruining all together about 6 AW 18350 batteries. In order to protect this from happening again I bought the 2 cent for safety and had a great vaping experience for about a week.
Unfortunately the Vivi Nova ruined the threading on my Stealth cap and it is completely unusable (meaning I am using an Ego now, quite a difference from my usual GG vaping).
In conclusion, the Vivi Nova is a great tank if the therads wouldn't mess up certain mods. I have a Caravela and a Super T Schockwave coming and was hoping to use the VN on them, but after ruining my favorite mod, unfortunately I will have to search for a different solution. Wish the Vivi Nova would have worked for me, great taste, vapor and easy handling but not worth ruining an expensive mod.