Waldemar is an excellent teacher on lighting. I just opted for this deal and have so far found it very informative. At present, I've not tried anything yet, but plan to do so on a render I did recently where my lighting wasn't quite right. He does send out quite a few emails for sure, but I just ignore what I'm not interested in. 

I have some of his earlier lightsets for DAZ Studio, but Studio won't render on this pc (never could figure out why) so I dove into poser and learned how to use it. This training is supposed to be usable in any 3d program, which is why I decided to get it. He does know his stuff and is a photographer in real life. 

The deal also gives access to his forums on lighting (and more).

Not trying to sell this or anything, just giving my opinion. It's up to you if you want to go for it.