Great thread. In trainers/fighters you get other time for sand bagging. I always considered this dual-received since the flights often packed in more learning then if I was actually on the syllabus sortie. Based on these inputs sounds like its better to just leave it off, which ended up costing me about 1% of my hours, at least none of it was PIC that I lost. Funny to think back that 1% of my flying was sand bagging .