The Halo Triton is a tank system, but you can use cartomers with it too. I got a 4 pack of XL cartomers with my order.
Haven't carried the Halo with the tank in my pocket yet, but carried it around with a cartomizer. No issues whatsoever. The starter kit comes with a cone that screws on and covers a good portion of the cartomizer. Makes it seem more durable to me.
If you're thinking size and portability, the Triton is far smaller than it seems. Here's some real-world perspectives on size, rather than measurements in mm (I have the 650 mah battery) -
The battery has the same diameter as a AA battery.
With an XL cartomizer, it's a little shorter than a capped sharpie marker (I don't have a sharpie around to compare length with a tank)
With an XL cartomizer, it's slightly longer than a Blu disposable.
- Its about 1 plastic top cap's length longer
- I'd imagine with a regular cartomizer it would be the same length or slightly shorter than a Blu disposable
If you can keep a Blu disposable on you comfortably, there's no reason you can't do the same with a Triton 650 mah battery and XL cartomizer. It's just slightly bigger. I was worried about it too until I bought it. So glad I bought it. I'm the type than never throws anything away, and I threw out my Blu disposable once I tried the Triton. The Blu disposable is a poor excuse for an ecig compared to the Triton.
As for tanks vs cartomizers, the tanks are so much better. The cartomizers are far more than adequate, but they're not in the same league. The cartomizers are perfect for on the go IMO.
Not trying to hype up the Triton. Just telling you my experience with it. I couldn't be happier. If all that's holding you back is the size of it, I'm pretty sure you won't have any complaints.