I had seen those vids a number of years ago but didn't quite get it until recently. The keys to the stroke as I see it are: using downward pressure instead of pulling back and pivoting the paddle at the grip instead of the middle of the shaft.
The downward pressure keeps the paddle vertical throughout the power phase and is equally pressured throughout the stroke. It also forces me to have a shorter stroke as the power phase is done as soon as the paddle hits the bottom of the rotation. As far as the pivoting the paddle at the grip like Puakea said I feel like the paddle doesn't pivot at all, but I'll take his word on it. The thing to remember is that there is no push with the grip hand or pull with the lower hand. Both hands move down together on the same plane.
After years of looking for the ultimate power stroke I finally figured it out by replicating what my wife was doing in the bow. A couple years ago I noticed that my wife's stroke had changed. She always had a strong stroke but what I noticed was she applied power applied equally throughout the stroke. With other strokes I felt a surge in power at a point in the stroke, but I wasn't feeling this anymore, it was all maximum power. When I asked her how she came to this stroke she said she learned it from our friend and professional canoe instructor in Hawaii, Chris. I don't remember getting the same instructions, so I either didn't "get" it or maybe Chris went over it with her while on the water where she was getting instruction that I couldn't hear because I was further away in the bow.