Firstly, you do not break apart scar tissue:
http://www.physicaltherapyjournal.org/cgi/reprint/69/12/1014
Massage can be a means to an end for treating dysfunction. Often though, massage by itself is a temporary solution.
Graston is 99% of the time is the result of a lazy practitioner. One of the few instances it is more beneficial is when you have a small practitioner working on a large patient. It helps give some extra leverage and allows extra force to be used. However, if this is a necessity, if available, it’s better to get a larger/stronger practitioner.
Just because it takes you a while to feel warmed up doesn’t mean you have hamstring issues.
How can you say the best method for the patient is what it is most comforting for the practitioner? Hand massage is not comfortable. It’s damn work. Just because moving specifically molded metal is a hell of a lot easier than using your hands does not at all mean it is better for the patient.
Also, if you have a practitioner working 8 hours a day what’s most comfortable for him/her at 9am is unlikely going to be most comfortable for him/her at 4:30pm. Yet, if the first client of the day and the last client of the idea have the same exact issues, what’s best for the patient has not changed.
How did he diagnose your hamstrings as tight? What issues at the hip did he state?