Which of the 3 rife machines work best is a good question. I don't know that I have an answer as I use them both. We have a third machine that is a single setting machine that has never been used and is in a closet. On my older version machine I can program in a chain of settings. Maybe 20+ selections. On the single setting machine only one sequence (or setting) can be run then a new setting has to be programmed in. I know that machine cost a lot of money but since we have more user friendly versions it just got put aside. I don't know how many versions are on the market but I feel that anything with a manuel that lists conditions and the appropriate settings to treat is what you want. I would look for machines that specifically list conditions you know you want to treat. For example I would love to find a setting to treat hormone loss as in menopause. It just makes sense to me that the hormone production center should be able to be re-aroused. I also would look for one that treats dental decay, hiccups, weight loss, dry skin, wrinkles and astrological. Mine has 2 settings; one for Capricorn and one other, I forget which, but by now they should have all 12 mapped out. Good luck and go for it rifing is good!