I kinda have trouble calling this a cart. To me it 1/2
tank and 1/2 cart. I noticed it after the Ego Tank and before the 510 tank came out, which has probably supplanted it. You might want to check them out. I believe they have gone over well.
I used ego
tanks for months. One atty finally had some of the problems people had mentioned, and then another.....so it's not as high on my ranking any more. But even so, recently after a bad day, I pulled out a new one and it was like a wonderful old friend!
And, I have a friend who uses a type of mega cart and has been for well over a year and has no plans or reason to change. Like many of us, she preferred the larger & longer lasting batteries & this jumbo cart suits her to a T.
There is no need to change-----but it sure can be fun!
(edited due to typing error --- for the record --
cart = cartridge (hold the filler and feeds atty) add battery and have 3 part system.
carto=cartomizer (combo of cartridge & atty) -- add battery and have 2 part system.)