I dont get the insomnia and jitters when my test dose is low. I personally think those side effects are from the high estrogen from high dose test combining with high progesterone. As for the increased metabolic rate, I think test increases it as well because of increased IGF-1 output and its a strong androgen that locks on to fat cells. Tren just does it much better because its 5x as androgenic, increases IGF-1 more, and has nutrient partitioning properties that push calories more into the muscle rather than into fat.