I have to agree with timekiller, this product was not worth the $100. The code generator is basically a fancy version of the free D-Form Joomla 1.5 template builder extension. The Videos were informative but the Audio is really bad in places and not a great deal is actually spent on the Template Kit because there isn't a great deal to learn. I will however say that the ones on how Joomla templates work gave me enough info to dive into the joomla template documentation and code directly and start manipulate the templates myself.
The J_CSS_Designer is a neat way of visually seeing what effects you are having on your templates but you can do the same thing by viewing your local website after applying changes. I think Brian is onto a good thing here, going by all the positive reports, but I for one was disappointed on what I got for my money.