I recommend both. Training in a class environment gives you the opportunity to work with different personalities, which is important for when you are on the set. This also helps with interaction with the other characters and dealing with props. When you do one on one's with your coach, this is amazing because all of the attention is on you. You will have the opportunity to work on personal areas even more in depth that you are challenged with. When working one on one with a coach, that will always give you the edge for your auditions. That third eye is crucial. Now with innovative ways to train online (ie: smartactors.com), the actor has an additional tool to help speed up the growth process. The most rapid growth comes from a combination of training in class, one on one coaching via webcam or in person, and online classes from a reputable company (ie: smartactors.com).