It does depend a lot on you, for sure, and your personal preferences, study habits, and level of commitment. Based on what I've seen over the years as a teacher, and what my students say, I'd summarize pros of studying with a class as:
1) The set schedule of once (or twice, whatever it is) weekly classes at a certain time, with specific suggested homework assignments and a defined study plan. This is one of the things I hear most from students—that without a class to attend and study plan help, they would have (or did have) a hard time keeping up the commitment and staying disciplined.
2) The benefit of a teacher to learn from. A good teacher can show you multiple ways to approach different problems, and provide a lot of insight into the test and test-taking experience that you often can’t gain from a book. Plus, you can’t ask a book questions!
3) Interaction with other students, and learning from their questions.
4) Usually a larger wealth of resources are available with a course, compared with purchasing a book or basic online prep tool without a course.
Pros of studying on your own:
1) Ultimate flexibility—no class at a specific time; you can tailor your study plan to your availability.
2) Cost.
Some people are fine studying on their own, and don’t feel they need the extra structure and guidance that an actual class and teacher provide, so as I said, it depends a lot on your personal preferences.
Good luck!
Jen Kedrowski
Kaplan Test Prep & Admissions
GMAT Teacher
MBA Admissions Consultant
National Product Team Member