Hi Russ, if you want the opportunity to to complete an additional sim test you can do so by signing up for our trial here for free!
https://gmat.economist.com/We have over 5,000 questions. When we write questions, we use only the Official materials as a basis and emulate the tone, difficulty levels, traps, mistake types, etc of the Official materials. Many of our students score within the 30 point differential (+/- 30 points) they achieve on our exams. It is easy to fall or jump 60-80 points on two exams taken with the same amount of knowledge and the same percentage of correct/incorrect. But in general a student should stay within the +/- 30 point differential. The other advantage we have in writing questions is that when something changes on the GMAT (e.g. sentence correction questions getting harder since 2010) we can get right to work on analyzing what has changed and creating new lessons in the system and altering our algorithms accordingly.
Remember, the types of questions one gets on the real GMAT depends on performance and luck. If you are a strong student, then you will only see the highest level questions and visa versa. While you are studying with us you will see a much greater range of levels and types. If you are doing well, you will indeed advance to higher levels more quickly, but if you are having difficulties, you will see more measured practice to get you to the higher levels.
Moreover, the number of questions you will get on the real test will of course be limited compared with what you will see in your studies because GMAC only tests a limited number in its potential pool (37 questions in the Quant and 41 in the Verbal) whereas there are more question types than can actually be tested.
We have had students score in the 99th percentile; some started at a lower score while others already achieved a 700 on the GMAT and simply wished to boost the score. So, the most advanced material is indeed there for the student to learn. Our program is a fantastic tool and how you use it will determine how you do. Succeeding in the GMAT is not only about studying on 'real' GMAT type questions but applying the necessary techniques that we teach you.