Many folks in the TDI site Oil Guard because of the members who has a great reputation does not care to use Amsoil products. His contigent uses Oil Guard. The first filters used were Amsoil. A few others use the TP method, but not many. Most people do not want to be changing filters every few thousand miles.
I ran 53000 miles using BE-100 or BE-110 filters. The additive levels did not deplete, soot stayed within 3% limits, etc, etc. The Amsoil 5w30 oil is specifically forumlated to run a VERY long time. If you want to use cheaper oil that falls apart quicker then I suppose the TP method is fine.
I do have the spreadsheet of results, but don't have it convenient to get online. It was interesting that wear metals stayed fairly constant as the oil aged. Either because it continued to be filtered out, my engine had less wear, or other.
One of the neat things about bypass filters is less waste oil.