If I read 1 good valid murder mystery book, would I really want that to be the ONLY book on the subject? If my 8th grade history book was considered to be accurate by the majority would I really want to be limited to only knowing one author's thoughts on the subject? Or how about browsers and music players? Do I just want to use IE? It gets the job done well enough. So what's the difference between those analogies and fitness ebook, supplements and programs? Really there's no difference to me.