Having attended a full length course (testmasters), I can say that less (much) than 75 percent of the time was valuable to me personally. The routine is so prearranged that it may not be helpful if you have specific problems that aren't the issue of focus preset for the course. In my class during a 4 hour session you have about 30 minutes worth of breaks, the teacher spent about a full hour going over 4 LR questions in the beginning of the sessions and if you already understand 3 of them that is more wasted time. Then you would do some practice questions and if you understand the majority of them it's not really helpful to take an hour going over them. Unless you are just missing questions on the test left and right the pace may not be to your level.
If your classmates ask questions that you don't need to hear, or need help with things you understand that takes up more time. This was really a big problem for me.
Several of the classes toward the end are simply review and time crunch practice which you can do on your own.
Reading Comp was inefficient, we read the passages aloud then went over the answer, but the teacher did not explain why every answer choice was wrong, he would select - and this was the case with a lot of other things in the course - the trick answer he felt most likely to be picked and explain why it was wrong and simply cross off the others as unimportant.
For LG the teacher I found myself simply doing the games on my own and not really paying attention. He was constantly erasing and filling in different things and I found it hard to comprehend. If you don't understand how to setup games the class could be helpful, but I'd already gone over books that taught notations and such. Perhaps my level of preparedness prevented me from benefiting fully from the course.
I found the class to be very helpful for was the LR section. In this section we did go through detailed explanations of each answer choice and why they were wrong or right, and we had a through explanation provided for all of the answer types commonly associated with each question type.
The ratio of time spent in class to the number of test questions actually reviewed in class is not proportionate. This is why I think a tutor would be much more valuable. You can spend time on your own doing practice and have your tutor explain exactly what you didn't understand which is much more efficient and the time/question ratio is dependent on a pace you are comfortable with.
I know some people do rave about courses, particularly Testmasters and Powerscore, and tend to view them as more advanced than there counterparts. However, I felt they were very basic. If you are hitting at least 65-70 of the correct answers on practice tests, and/or have done self study on necessary and sufficient conditions and game setups I don't think you will find the course valuable and would highly encourage you to seek a tutor.
Hope this helps without offense or controversy.
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