I have the GGTB and I want to try some cartomizers. Right now I drip using a 510 atty. I didn't care for the 901 attys so I got the adapter for the 510. I would love some recommendations on what type of cartomizer to purchase and where to purchase from. I was thinking about getting some pre-filled cartomizers because I don't have anything to tell me if the they're DOA, and I'd hate to fill up a blank one and lose a lot of juice. Also, I've never used a cartomizer before so I'd like one that is user friendly if possible. Any suggestions is appreciated. Just as a side note - I'm using 14500 batteries.