I have purchased 3 different makes in the last 15 months, same problems with each, leaking, inconsistent battery life and cumbersome.
The e-pen eliminates all these problems, epen caps very good no leaks, battery holds charge well, good design very light easy to carry in pocket, easiest pen yet to keep clean.
I was a heavy smoker found with cheaper brands of fluid even using 36 mg I still had cravings, using 18 mg ecaps reduced my cravings far beyond anything else I've tried, I presume it's because of the genuine nicotine content and quality.