There is little or no flexibility. You have to sit through material you already know, and you have to speed through topics you wish you can spend more time on. When the coverage is hurried, many topics are skipped and you are required to spend a lot of time understanding your notes and studying more.

If you are busy at work or at home, and if you are not current with the coverage, the class becomes a waste of your time and your money. What happens if you miss a class? Can you make it up?

The time you spend commuting and the inconvenience of scheduled meetings often make this an unpopular method. What is the value of your time?