I went to a seminar about this system years ago, maybe like 20. And although the concept sounds good, pattern drafting this way is a bit cumbersome. And you will never get a perfect pattern with 'just two measurements', your shoulders may not be a size 14 but your bust is, or you may have a shorter torso and need to adjust back length. If you are interested in pattern drafting I suggest you check out
http://www.wildginger.com/
I have used the Patternmaster system, but before I made the commitement I used one of the Click It patterns so I could get a feel for it. Click it is also a good idea if you think you will just be making one specific kind of clothing like tops or skirts.
You can also check out Wild Things at the site, which is free and will give you a better idea of how the system works.