Yes. By training with a coach, specific details of your stroke work can be perfected upon and misinterpretation can be easily rectified. Such attention to detail would be very difficult in a group class. A group class has the advantage of dissemination of technique to many people at one time but each individual has their own interpretation and may not neccesarily perform the technique to the coach's satisfaction. The coach is unable to devote much time to the individual within a group class.