I have the 'Color Sanding & Buffing' one. I thought it was good. But, not being a pro, I can't really say how good. If you would like to take a look, I'll send it to you, if you are willing to pay the shipping to you, and back.
I have the one on metal working and patching. It looks pretty informative and has a lot of information packed into a 55 minute tape. I am planning on purchasing the other 2 on painting and color sanding.