Manhattan Review is excellent. I live in NYC and currently I am taking the 6 session course every Sat from 9:30 am - 2 pm. The classes fly by because they are very interactive and we go through problems in detail discussing both strategies and also general rules and knowledge (compared to the Kaplan course which I took 5 yrs ago and it was a big waste of money IMO).
My class is 3 people including myself! so we get great one on one attention. Teacher is great, scored very high on the verbal and knows how to keep the class interesting. I haven't started the math sections yet but verbal has been great. For the class breakdown, we quickly go through each chapters summary, you are expected to read all that pre-class. Majority of the time we go through sample problems from the
OG verbal guide and MR verbal books. We will do about 10 questions and then discuss answers. I really like how the teacher goes through each answer, showing us what the mistakes are and what to look for. I just found it very refreshing to see how a 700 level person looks at the problems (completely different than what I was used to!).
I highly recommend this class for people who aren't very good with standardized tests and/or aren't very good studying on their own. You have to know your own study habits before even considering the GMAT. I have friends that got 1 book and took 2 practice tests and scored a 770. But they just knew all the tricks in the book and have been doing standarized tests for a lifetime. For me, I needed a little more structure and also guidance on taking standardized tests.