To add to what Cash said, the reason the 14500 batteries are an advantage over the eGo is that, not only are they cheaper, but they are user replaceable. All rechargeable batteries have a finite number of charge cycles during their useful life. With the Icon, you simply replace the batteries, which you can get from a number of places for around 7 bucks each. With the eGo, you have to trash the whole unit and buy another one.
Other advantages the Icon has include:
It's all mechanical. That means you can service it yourself if necessary. However, there's nothing to fail in it either. It doesn't rely on internal circuitry. Really all you have to do is clean the contact screw and post occasionally. I do mine about once a month, if that. And you can replace any parts yourself as needed. For example, if you lose your spring or somehow warp it, you simply replace it. Pure Smoker sells replacement springs, but you can also get some at your local hardware store in a pinch.
It has a locking button. So that means there will be no accidental activations in your pocket or purse. I believe you can buy button protectors for the eGo. But with the Icon, the protection is built in to the device.
The eGo and Icon are roughly the same size, but the Icon is a bit heavier. That's not to say that the Icon is heavy in its own right. It's just a testament to how extremely lightweight the eGo is.
I have both, and I can sum it up this way. I like the eGo a lot. But I love my Icon.
