I agree that video looks like a scam, but the guy could have a good idea and just not be good in front of the camera, and obviously he isn't.
As for maintaining spine angle, some people can't do it just because of back issues not lack of talent.
As for swing speed, I don't know where it comes from but I hit the ball a bit farther than with my conventional swing when I tried it last week for 6 holes. 5 of 6 fw's too, with the 6th being just off. Now, I'm not a big hitter and my normal swing features a collapse at the top I can't seem to get rid of so maybe those "half" swings were keeping my arms lower where they couldn't collapse hence better contact. I was in the 235-250 range where normally I'm 220-230.
As to direction, I hit every ball dead straight. The irons (I was using my conventional clubs) went quite low as did the one 3 wood I hit off the deck but everything went straight, I'm thinking the trajectory might be because of the short club lengths? Who knows. I know I saw enough to be intrigued. I have a tournament this weekend and if I can get out beforehand to try this a little more in depth I may use it to start. I really don't get to play except once a week.
I did try my Frankeniron pw built to 39" and it was no bueno. Felt too stiff and head heavy. I was just in a field near my house and only hit 5 balls but it didn't look promising. For this to have any chance to work to me, I'd need to grind a ton of weight off the head, not worth the trouble.
So I hope to give this swing one more shot than back off to youtube to see what else I can find to dabble with. It's like a hobby to me. I should have kept track but off the top of my head these are a few I've tried:
Peak Performance Golf
Ron Del Barrio
Square to Square (two versions)