How useful are in-person classes?

It depends on what you respond to. Some people prefer live classes, and some prefer online instruction. Online is almost certainly going to be better in terms of pacing, as you can choose the speed at which you go through the course (most live classes aim for the "middle"). Live will certainly be better in terms of personal attention, as even those online courses that offer support assign a lot of students/queries to each instructor.

Here are some useful resources for your search:
https://gmatclub.com/forum/best-gmat-co ... 67728.html

Here are the main values of the Class/Online Course when compared to Self Study:

• Access to condensed and comprehensive materials - traditionally prep companies have saved the better books for the classroom courses. However stiff competition is eroding this advantage. I am not sure if Manhattan uses anything other than their regular books + OG 2018 in the full course. Veritas Prep does the same thing I believe. Kaplan on the other hand has a new course with new curriculum that's different from their books.
• Saves Time - you are told what to study, how, and when
• Confidence that you are studying everything you need to cover and not missing something
• Access to help and an expert
• Schedule that drives and makes you study (very important for some)

If you feel these advantages are worth the money and you want to give it the best shot with wasting the minimal amount of time - then the class is for you. I would be interested to hear more but in my experience, most often the reason people are taking class are: to push them, to keep them on track/schedule. If that's important to you - then absolutely get into a class. However, you said that you do not need to be pushed, so I would say in your case, you may not get as much out of a class.


Also, a number of folks discovered that they can do self-prep first and get to a 650-700 level and then top it off with a "money back guarantee" prep class - allowing them to get the best of both world...