Thanks for the post 9 ball, I really enjoyed putting Guaranteed Improvement on DVD. You guys may be correct on the aiming system, it can be tough on some people to get in touch with that contact point on the front of the cue ball but there are others that can and the way I see it is even if you have a tough time lining up those two points at least you have a precise answer to begin with and then maybe you can approach the shot any way you like. Contact point answers can translate over to other methods like equal portions, ghost ball, edges, tip aiming and so forth.
While doing the aiming workout you don't have to aim by the numbers to complete the workout (but I do think knowing the answers helps), the workout is design around pools more missable shots that come up quite often, shots that all decent players should become much more consistent at and for those that stick it out they see those misses drastically reduced. Keep up the good practice.