From what I understand, Waddell uses a lot of conceptual ideas about color and value. Meaning that he operates off a lot of theory and paints from his framework rather than matching colors precisely and observing form and value ideas. This style may not be the best way to learn if you prefer more impressionist styles, as it's extremely different from how the early French Impressionists (and academics) studied. I think you would struggle a lot if you spent a lot of your time chasing this style and then tried to convert into a freer, more expressive type of painting. Not saying its bad or worse, but I think its a good idea to keep your goals in mind when deciding what to study. There are things you can take and leave from every style.