I just wanted to say I've been vaping now for about 4 months and have really enjoyed it. I started out using the prefilled carts, just because those were the easiest to use at first. After about 3 months using those I decided to try getting blank carts and just fill those with the bottled juice, which cut down on the amount of carts I was buying tremendously! However, I'm a chain vapor...I generally went through about 3 carts a day. I was using the titan batteries which were really nice, but was having to switch between 1 or 2 batteries a day. Finally, I decided to take the chance and order me a XL DAV and a 6ml tank. When I first got the battery and tank and put the two together I was like , "OMG this thing is huge!" Which it is compared to a titan with a cart, however, I've been using it for 3 days now and I absolutely LOVE it. Yes it's bigger and heavier, however, I have been able to vape ALL day, from about 7am till 11pm and the battery has yet to die. Also, I only use about 60% of a full tank. I have plugged the DAV into a USB charger at night before I go to bed, and by the time I leave for work in the morning its fully charged. I'm still learning what's the best/easieest way to fill the tank, but it's a pretty simple process. Anyway, I just wanted to give my two cents to those out there who may be considering going from carts to tanks, or to the DAV battery.