i have experience with this. i took my post bac at two schools--one very easy school, and one very hard school. i would say the answer to this depends on how much you would like to learn. im a nontrad applicant, so my post bac consisted of the basic sciences. i took chemistry, organic, and bio at the difficult school. i must say that although my grades were lower, i learned alot from studying so much and was able to perform pretty well on the DAT with only 1 month of studying. my highest scores on the dat were in bio and orgo. next i figured that physics isnt important, so i took that at the easy school. although i received A's, i learned absolutely nothing and taking that class made my brain lazy. i also took human anatomy, which is a typically hard class, but at this school it was a joke. so if you would like to be better prepared for how difficult dental school will be and would like to be better prepared for the dat, take the classes at the difficult school and challenge yourself to do your best. youll feel a sense of accomplishment when you do! if you would like a boost in your science gpa without any regards to what you learn, go with the easy A school.