I came across this some years ago and thought it was perceptive, if somewhat biased (the author is President of SMART),
If Not AA, Then What? SMART Recovery and the AA Alternatives | Huffington Post
"...non-12-step groups can be more positively defined as self-empowering groups. Self-empowering groups encourage individuals to take charge of their lives and leave addiction (and eventually recovery) behind. In contrast to the 12-step approach, self-empowering groups support individuals in taking charge of their lives rather than accepting powerlessness and turning their lives over to a higher power....
The 12-step approach is a serenity approach to recovery. The self-empowering approach is a courage approach. As the Serenity Prayer suggests, we all need both serenity and courage. However, most of us prefer one approach to the other. To use the language of scientific psychology, some of us tend toward external locus of control (serenity) and others tend toward internal locus of control (courage). Locus of control refers to our expectation about what in the future will shape our lives more (e.g., what controls us, or who is in charge): What happens to us, or what we do about it.
Self-empowering approaches to addiction recovery are well-suited for individuals who have an internal locus of control. Rather than thinking they have lost control of their lives because they have a disease, these individuals want to learn how to build motivation, control craving, resolve their underlying problems, and move on with creating meaningful and purposeful lives...."