The Sedona Method is more well known, but I've used it and the Release Technique for a couple of years now. I've tried dozens of programs and releasing really has done the job for me.
I think the Release Technique goes a lot deeper and I think it would take most people farther. In studying the work (it's based on discoveries by Lester Levenson) it holds truer to the design of what Levenson discovered. Sedona will tell you otherwise, but I don't think that's true.
My personal opinion is Larry Crane dedicated himself to mastering this information while Hale Dwoskin has used it as a vehicle for marketing and making money. Hale knows it and he's good, but it is a totally different level of experience with Larry Crane's Release Technique.
I learned the SM first and if it had been the other way around I don't think I'd have felt the same.
I think different people respond to different approaches, but I'd buy the Release Technique course as soon as you can. It's simple and my results have been profound - truly. It's an awesome course and the more I do it, the better it gets.
Best wishes, John
