Here is my opinion:
Vivi's
Battery is always bone dry no leaks from there.
They are consistent taste mostly the same.
So easy to fill no messes, easy for older ppl that might not have steady hands or patience.
No setup and can get replacement tank.
Can have dry hits if you do not pace yourself and tip.
Works very well from full to 1/2 full then it goes downhill. The less juice the more tipping and swishing and taste seems to diminish.
Juice will come up the drip tip once in a while but is easy to clean.
Carto Tanks.
Taste can be spectacular or can be horrible.
Pre punched can work well or not with your juice.
You can make a horrible mess when filling and takes a bit of practice to get it right . Even then you will still probably do some once in a while.
Battery is always wet if it isn't you will get dry hits.
If you punch or dremel it takes a bit of skills tools and patience not allot of ppl have all 3
They seem to last very long or not.
Almost never a dry hit when in a tank if you are conservative on your voltage.