I train in Shotokan and have a couple of Kung Fu tapes. To be honest I am pleased to be able to learn from video something that likewise I would not otherwise get a chance to. At the same time, even with a difference in style I can understand the basic principles of the stances, movements and strikes, and my Shotokan classes help me train in speed and awareness. I think videos are good that way and I like to think I am learning something extra. I have used Tae Bo videos just to keep fit over the last couple of years before actually taking up a martial art and my instructors were quite surprised at how well I was able to practice the basic kicks and punches and how flexible I was. I think you have to take what makes sense to you and that you can internalise from every source you can and neither totally dismiss one way of doing things nor only accept one way of doing things.... Yin and Yang baby!