Were you trying cheap carto-based systems, like Blu or Sky? That tends to happen with the cotton-based models, I find - at least, for first-time, or novice users.
That being said, I've had a lot of people who've tried various set-ups of mine (w/ clearomisers/tanks), and a lot of them - all smokers, btw - have coughed, and asked me "how I handle it". Truth be told, I think it just takes a few gos to get the hang of the throat hit.
Also, with the right set-up (a variable voltage device), you can adjust the amount of warmth, and with the right juice combo (less PG perhaps), you can control the amount of throat hit.