I took a look at some of his videos and I didn't feel good about what I saw. He probably knows his stuff and the techniques, my concern is that I saw some vital gaps in his sparring and application drilling that made me feel really uncomfortable.
If his video is just covering concepts then you should be ok. If the video teaches applications then you are probably won't see the results that you think you'll see. For example.
I see stuff like this and I think. "trigger the guard and break the ribs". He's using the wrong guard for the type of punch that he's getting.
It's things like this that makes me uneasy because instructors pick techniques to use against certain strikes and then teach that application. If they don't have a good understanding of application beyond demo mode, then they will end up picking using the wrong technique for situation.
I understand what he's doing in the video, but I'm good in 2 things when it comes to martial arts. sweeps and elbows and I know without a doubt that you don't use elbows against a jab like that. If the DVDs are teaching to do so then you didn't get such a good deal.
When I see stuff like this, I think, just point the knife at the neck @0:21. I understand it's a demo and drilling but there are certain things that should always be in the front on your mind such as where your opponents hands are in relation to you body.
Again I'm not saying the other stuff isn't good. I just saying that what I saw from his previous videos makes me feel uneasy in terms of application.