I believe that Knewton has an extremely good learning platform. Technically it is a superior system. That said it is not for everyone. I took it this summer and was put under some real time constraints because I was taking six hours in graduate school (digital forensics/computer science) at the same time and it was a real strain. Knewton reduced me to tears a number of times because it is not a "positive reinforcement system" for students that have been away from the subject matter a long time. Yes, I am an extreme case because I graduated from high school in 1969. I never, never, never would have thought about going into a PhD program until this "wonderful new economy" that we have convinced me that standing still is not an option for anyone. Knewton's instructors are positive. They provided me with a list of resources so that I could begin the process of catching up. On-line classes, however, were not a positive experience because I was too far behind. I'm not sure about their practice sets and exams also. It is real easy to get negative feedback that reinforces a bad attitude about the GMAT. The Knewton concept videos are tremendous and really help. I will take the GMAT for the second time on September 22nd. The first time was early this summer before Knewton. I've been going to a sports psychologist for several weeks, working with creative visualization, and gone back to an exercise program in order to increase my competitive edge. Why? Well, Knewton is great, but in my opinion it falls flat, like almost all GMAT review programs, because it doesn't build a mental edge. You are trained to review and answer questions, but it is extremely easy for the program to become a negative experience that does not build you up for the exam. Yes, I'm an extreme case, but since I'm in the process of finishing my second master's degree this semester I've already proven I can do graduate level work, so what does the GMAT prove in my case? My advice is that Knewton is at the top of the pile with respect to review courses, but it can't be the only leg under the table. If it is than you better hope that it is the center leg and that you are using the material just for "REVIEW" purposes. Otherwise you may be disappointed, which is, of course, possible with all GMAT review courses.