I have used both 2 dial and 12 dial instruments. The instrument is not important. They all do similar things. The important thing to consider is what a good instructor uses. Finding a good instructor comes first because - pehaps he/she may teach with a 2 dial machine using american rate system. How will you compare your future results to an instructor's results ? I purchased a 12 dial machine, but could find no one to train me on it. Purchase a machine either a friend or an instructor you learn from has. You must have a source to check your readings with to be sure you have developed proper readings and protocals.