All actors have different strengths and weaknesses so be wary of a one size fits all approach to acting, a good coach will work with each actor individually within the classes to develop their talent. Something else to consider is class size. If the classes are filled to the rafters what are the chances of you getting that much needed 1 on 1 time with your coach? Getting 5 minutes a week to share a scene is going to take you longer to develop. As there are so many part time studios/schools to choose from, make sure you go with the one that resonates with you.