I have 4 vivis and I love them, good out of the box, great after making the vents larger, I have the short wicks and had a bad experience with one with the long wicks. They are a great alternative to cartos, but I still love my cartos. Its a little less on the volume of vape after it hits the halfway mark on the tank, but little swirl and tip, it goes like a steam train. It needs a little breaking in, it gets better and better after the second fill and on after that.