Just to give you some background about me. I am an engineer and non native English. So when I decided to embark on this journey of GMAT, Knewton looked like a great option. And why not, they have 50 points money back guarantee. Anyways, my hope was not that if I score less I will get my money back but that the course material will be very competent. In the hopes of getting a score of 700+, I signed up with knewton in february. After I finished knewton course work in march, I took Manhattan GMATs free test, in which I scored 600. I was completely shocked, since I thought I was reasonably good in quant and was improving reasonably well in verbal, at least according to Knewton. I realized very quickly that it was not me, it was the poor quality of Knewtons class. I bought
Manhattan GMAT's strategy guides and started preparing. For non native speaker, there cannot be a better guide. At that point, I realized I just gifted my 600 dollars to knewton. Knewton did not help me even a bit to say the least. But then I cannot claim any money back as I have scored more than 50 points, though on by my own effort, nothing to do with Knewton. I wish I could just take that money and give it
Manhattan GMAT.
The classes from knewton are extremely basic. They are good enough if you want to score up to may be 650 at best (even that I doubt). The whole question set is based on
OG's. I have taken GMAT twice and guarantee you
OG is in no way representive of actual GMAT. Questions are much harder in GMAT. Furthermore, Knewton 5 CAT's poor at best. Some questions are plain
OG question with some numbers changed. And their scoring extremely poor. To give you an idea, I scored 580 in the last Knewton CAT, a day after that I took GMATPrep (although I got two SC questions, for which I knew the answers, from
OG) and scored 740. Long story short, if you want to join a course, just join
Manhattan GMAT. Don't get fooled by 50 points money back. If you don't have money to spend on actual tutored class from
MGMAT, take it's self prep, trust me you will be better served than taking Knewton's.
I only have experience with these two coaching services, so I dont know anything about other coaching classes. (Everyone thinks Manhattans are the best anyways, why risk it). Trust you will not go wrong with
Manhattan GMAT. And use their forum as well. There cannot be anything better than their forums. The first time I took GMAT I got 670 (of course I got really tired in the middle of the exam and started loosing concentration). For the second time, all I did was to go through
Manhattan GMAT's forum. I scored 730. In fact in the middle of verbal section the questions got really tough, so I just guessed on couple of questions so I can get easier questions and save time. In the end though, I was left with some time. In short I could have scored more. But oh well, I am pretty happy with my score. And I dont attribute even 10 points to Knewton. Like me, lot of people may not have much money to spare. Dont waste your money on Knewton.
Good Luck!!!