Up until about a month ago, I could not get a single tank to work right. One hole, two hole. Nail, Carto punch.. nothing worked. Cartos would get stuck, juice would not wick etc etc. Extremely frustrated. Finally, it was recommended that I watch a video on slotting cartos using a dremel. Suddenly the sun broke through the clouds and the angels started to sing for me..
Now, everything works just as it should and I have not had a single issue since.
I am using DCT's (have 4 on the go) with Smoktech single coil XL cartos and am confident enough in the process that I have even acquired a custom Phiniac Tall Boy tank.
That being said, I have had no luck with the Vivi Nova's. Version 1 or 2.5. This may be attributed to my ADV being a stubborn juice that just does not like wicking systems that any inherent flaw in the Vivi itself. Love how it looks on the Provari, but it just does not work.