Good observation. I faced the same problem after taking 3 MGMAT mocks. When i took the GMATPrep I was back to square one. The point is you have to start over with SC preparation. MGMAT SC questions can be solved easily with splits itself. They are very easy where as GMATPrep SCs are the hardest ones you would ever find for SC preparation. So read MGMAT guides again and start over SC. There is no other go. Be happy that you found out at least now rather than at the end. How about your accuracy in CR and RC ? Watch out for RC, that will also be inflated in MGMAT as far as i know. MGMAT RCs are more straight forward in everything compared to GMATPrep RC, be it main idea or inference questions. If you are aiming for 35+ in verbal then your RC score plays important role, you should make no more than 4 mistakes in RC so that you make less continuous mistakes and give space for improvement. My RC mistakes almost doubled in GMATPrep compared to what I got in MGMAT RC. On a final note, MGMAT quant is quite reliable but verbal is quite deceptive or not up to the mark if you are scoring in 650 and odds. Not sure if the questions are up to the mark when you score beyond 700 as in you will be getting more 700+ questions and they might be up to the mark as many people get the same score in GMAT Prep as well. The problem is 650 level questions in MGMAT verbal is equivalent to 550/600 level questions in GMATPrep. Always be cautious while taking other test prep company mocks. Hope this helps !!