Also, if you have taken either one, are these online tests full exams, or just partial? Are they better than the PR diagnostic exams, for example? I'll definitely be taking AAMC and other tests too, but thinking of starting with these as a full length practice.
If it's free and it will help you practice, then take it, why does it matter how it compares to others. Practice with whatever is available and as much as you can. I took them, and regardless of whether or not they are as hard or easier than the real MCAT or other practice exams, it will help you get exposure to the questions and the timing. Take the AAMC tests spread out, taking the newest ones as you get closer to test day, these should be your best indicator.
