E-cigs vs. Regular Cigarettes? How to quit?

[-3shelbylynn4-]

My boyfriend has been trying to quit smoking for almost a year. He just can't seem to do it. For now, he is just using E-cigs, but uses them very often. I would rather him use these then smoke cigarettes though. What are the risks of using this E-cigs on a regular basis and are they hard to quit? And should he slowly lay off the E-cigs, or just quit cold turkey?? Any info is highly appreciated!