I've made films for a few years and I took Solar's Light & Shadow workshop a few months ago. I wasn't quite sure at first, but it turned out to be great. I liked their practical and no-nonsense approach. Their price is quite reasonable and you'll learn a lot.
Hope this will help you make your decision.
P.S.They also have an excellent lighting workshop, which I also took (great thing about living in NYC :D). You should check it out as well (http://solarnyc.com/lightingworkshop/).