THe Kaplan Course is very rewarding, when u got the Kaplan Course Book, for a cheap price, less the official guide's retail, and u dont pay the 1200$ crap, for some instructor that just studies the answer's b4 each class and got a 90% on the GMAT, the Books are the best on the market, and show each type of question and provide good practice, althouhg in the study guide, I wish there were more practice sets, but free is free, good spring board to OG.
Kaplan Course is very lazy they hardly change their materials, as its the same questions from 1997, in the current versions.
In addition, Kaplan uses the question in their course in the GMAT 800 books.
I'm curious to how many new questions they add each year. Kaplan just redesigns the Course Books for their class so they LOOK NEW.
I think I have some kind of prediction that people that take Kaplan avg, about a 650-680 on the GMAT.