For verbal, the 30 min exams were about 1 point lower on average.
For physical sciences the 30 min exams ranged between 2 and 4 points lower (depending on the subject).
For biology ranged from being right on to 2 points lower depending on topic.
Obviously these 30 min exams are not a good indicator of a real MCAT. Not only were they intentionally made a little harder, but there is no way being tested on one single topic (i.e. translational motion) representative of how you will do on the MCAT.
However, they were not made to tell you how well you will do- that is what he AAMCs are here for. The 30 min exams were included to help you hone your test taking skills and to get you used to answering MCAT style questions on relavent topics.