There are vast differences between one consulting company and another.
Many consulting companies out there today are former dentists or office managers that have developed systems for their office and then marketed their particular method as though it will work for all other practices. These tend to be "cookie-cutter" approaches and very likely will not fit your practice or your particular management philosophy.
You want a consulting company that has years of experience and one that will do a full on-site evaluation of what you need. Then based on your individual situation, tailor a strategy and application for your specific practice.