A cartomizer in a cartotank is my favorite juice delivery device.
Drawback of a cartomizer used solo is you can't see the juice level within the metal cylinder when a drip tip is on. Also, once you have vaped a few drags on it, the filler within will look dry at the top, even though the middle and bottom will be saturated with juice.
But to me they provide the best flavor of any other the more common juice delivery devices, especially if within a tank. The carto will need to have 1 - 3 small holes in the shaft to allow juice to enter from the tank. Suction created by taking a drag encourages more juice to enter the carto. Advantages of a cartotank over a cartomizer used solo is the extended time between needing juice refills and being able to see the juice level.
It's all explained better with pictures and videos in this blog post I created:
http://www.e-cigarette-forum.com/fo...e-delivery-attachments-page2.html#comment7857