I met Jeff when I started playing again in '08, he was teaching out of Gates/JCC in Denver. Always found up him to be engaging and able to work well with people. He excelled with good Jr players and open level adults. He was always quick with a quick tip or piece of info if asked though.
I make it a point to check out his items on YouTube and when he worked on that 4.0 to 4.5 project blog.
If I didn't have a pro I enjoyed working with and who has a good technical plan in place for improving my game I'd sign up for his website. If you like the technical part of it, he's a great person to learn from instead of just hearing "good, good, good" from someone feeding you balls over and over.
If I were a former ATP pro and NCAA champion I'd promote the hell out of it as well.