John,
It does seems that everyone does the pretreatment process differently. This is because there are so many factors to be considered in the pretreatment process (i.e. the fabric, the color, how much pretreatment to put down, how to evenly apply it, what pressure to cure the pretreatment,...). Change any one of these factors and it could change the outcome. Also, the description of "lightly apply pretreatment" from one person to another can be completely different. So everyone comes up with a slightly variation in the process. Now with the new SpeedTreater from Equipment Zone, it sounds like the process has gotten a little bit more consistent.
Ultimately, you are going to have to find out what your pretreatment process is and this can only be done by a lot of trial and error. So absorb as much info as possible and keep a log as to what you do on each shirt (I recommend using both sides). This will help you be able to repeat the process once you figure out what works best after the wash test.
Mark