AAMC beats everything. You have the actual author of the exam and the materials that new test writers use for reference when writing MCAT passages and questions versus a commercial resource. It doesn't matter which company it is that you wish to compare to, AAMC materials are the better option.
There are enough free resources out there to have plenty to review, so if you only have money for one resource, make it the AAMC exams and section banks.