The eGo-T was my first set-up that I got above and beyond gas-station ones. I loved it at first. The batteries would last me most of the day, I could go a whole day with 2 batteries. The tanks on it are okay. I wouldn't point anyone at it that was looking for a tank system though. It holds quite a bit more than a cartomizer, but it's not near as much as what they're calling tanks now.
I used to carry around 3-4 filled eGo tanks with me and they would last all day. I didn't love the pipe-style tip though.
The eGo-C might be a better set-up if you're looking at long-term affordability. The heads are a bit cheaper than replacing attys when they go. I haven't tried it though. They also have adjustable voltage batteries that are available for the eGo-C.
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I use cartomizers, myself. I have 8-10 of them filled, and I can go through half of them in a day. I never got into dripping for some reason. Cartos and tanks are my thing.
I think just about anything that you will find is going to do pretty well for what you're looking for, but make sure you get spare cartomizers/tanks/etc, to fill up for the day.
Or if you're in a vehicle 90% of the time, you could get an ego-passthru and then a power inverter or a usb plug for your power point. Those use the power from the plug when you're using them plugged in, and have a battery in them for when it's not plugged in.
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