I have prepared GMAT in 2015 with Mubasher and got 680 in GMAT. He was such a best teacher as well as motivator that I always got encouragement when I need little push at time of failures during GMAT preparation with him. It was like a professional training of mind at start of preparation. How to do quick calculations without use of calculator? He addressed this issue at beginning of preparation pretty admirably. I was bad in critical reasoning and word problems. I learned good strategies from him and then able to eliminate wrong answer choices easily that were out of scope or irrelevant. Pre-thinking helped me a lot in getting my desired score in GMAT.
I recommend everybody who want a decent score in GMAT, if you pay close attention to your focus, you can never select trap answer or an incorrect answer choice. Be focus oriented and never loose it at any moment during your exam. It requires huge stamina, and Mubasher is the best teacher for me who perhaps know how to deal in such situation when I was in that problem. I was loosing focus after few questions. So his acumen advises and training has helped me alot to maintain persistence and concentrate on my focus. Emotions must be kept aside while solving questions.