As you already see, you are going to get mixed thoughts.
I personally have owned three Vivi Nova SVD's(The ones with the aluminum sheet over them and the two windows). I thought they were awesome back when I was a newb, but soon enough I started having huge issues all the time with each of them; leaking like crazy, dry hit central, horribly muted flavor, and let's face it having to vape with your pv upside down is irritating and a lot of time results in gurgling and
juice all in your mouth. So I tried IBTanked Carto tanks. They were a million miles better. No leaking, better VTF. However I quickly developed a love for trying different
juice and having to dedicate a brand new carto to every different
juice got irritating and cartos tasted bad after a week of use. So I heard about the Protank from the wonderful Exodus and I have not looked back since. Glass clearly beats the Vivi Nova plastic, no leaking, way better flavor, vapor, and easy to change juice(no waiting for long wicks to dry, no buying a carto for each juice), it didn't have an insanely tight draw. I now have the Protank 2 and two PT 1's. The Protank two fixed all minor issues of the Protank one. I love them. I also can vape them without worrying about having my PV upside down every time I take a vape. YMMV
But I think the Protanks are an easy win. It seems like taking 5 steps back to even consider a Vivi Nova.