In my opinion it's the majority of the responses in threads like these that detract from an otherwise informative site. I know little about D.R. but I’ve read up on how he approaches grip and recoil control/mitigation and his technique appears to be solid. It relies less on grip-strength and friction against the sides of the gun and more on leverage against key points to resist recoil and muzzle flip. I view it as simply another option for approaching the fundamentals for shooting in a very non one-size-fits-all world.
It’s hard to ignore the success of the Modern Iso, thumbs-forward grip and technique as demonstrated by today’s top shooters but that doesn’t mean that another approach to solving the same problem can’t be evaluated to determine whether or not it adds value. The few shooters I’ve seen using D.R.’s approach seem to shoot very well.