My experience (personal and from a few friends) is that there's a step function. A small amount of initial meditation gives some immediate benefit. Continuing t

My experience (personal and from a few friends) is that there's a step function. A small amount of initial meditation gives some immediate benefit. Continuing to do that same thing yields little more. Further benefit takes a much larger effort until new plateau. Specifically, I think there's definite short-term benefit to be had from small amounts of relaxation-oriented meditation, and from the common teaching "don't identify with the feeling" ("I am angry" vs "I notice anger is present"), allowing some freedom in reaction different from acting out the emotion that is felt.