It is very hard to tell which test would be better for a student. It is analogous to selecting a sport for a child and telling them to become a superstar without witnessing their development. In short, taking a practice exam can help students figure out which exam they like but not necessarily which one suits them. Unfortunately, the pACT is a highly unreliable predictor of future ACT performance. The PSAT is a great predictor of SAT performance but the reported percentile should be ignored.