I would say that all the models you bought other than the Kgo were crap models. When you think of what you pay for any of these models (assuming you didn't buy some of the over-hyped, over priced models), it's hard to expect these to last for years.
There are models that come with lifetime and/or full 2 year warranties, which is what I use. The old adage that you get what you pay for has merit. Get one of these better models and you will not have these issues for the most part. Atomizers, cartomizers and tanks need to be viewed as consumables.
Price is not a differentiator. For example, the Elite 808 starter kit and the KGo starter kit are roughly the same price. Not only that, but the KGo had a fault right out of the chute as well. There's been no distinct dependability difference across any of the models I've tried. That's the main point and why I posted the original question.
Additionally, no one expects years and the fact that something is a consumable doesn't justify a high rate of failure out of the box.
Re-writable dvd's are consumables and no one would accept the same rate of failure and/or poor quality that I've found in cartomizers etc.