I think this depends upon the individual trying to quit smoking. Both methods have success stories, and I see no reason to say one way is better than another. Whatever you think will work best for you.
When I began
vaping, I vaped as much as I wanted. If I got a craving for a cigarette, I vaped more frequently/harder. If that didn't work, I allowed myself HALF of a cigarette.
I continued this method for an entire week. As the week wore on, I found that the cigs didn't satisfy and actually started to taste bad. I began to prefer just
vaping. At the end of the week my last pack of cigs was finished, and so was I. I haven't touched nor wanted a cigarette since. 15 months and counting.
I'm a firm believer in a saying here on ECF. "It's not the number of cigarettes that you smoke that count, it's the ones that you don't."