I know this thread is old but wanted to bump it because I've been trying out this MGS swing recently and IT WORKS.
Couple of things about the swing as it has been discussed here that I think leads to confusion:
Pre-set/pre-turn: There is a false conception that MGS has no backswing because of the pre-turn of the torso to the right at address. Of course there is a backswing, you are raising the arms up (specifically the lead arm up along the chest).
Wrist cock: I think there is naturally a degree of wrist cock simply because the weight of the club naturally causes the wrists to cock near the top of the backswing. However the idea is to not add any wrist cock or do it excessively. The only thought should be raising the club up along the chest and letting it fall back down.
Power: There is absolutely nothing in this swing that would or should limit power or club head speed. There is definitely a weight shift in the swing but it is solely due to the weight of the club. I get much more distance with this swing, it feels free-flowing and promotes a natural draw.
Only for beginners/seniors/etc: I don't see why this would be the case although it is clearly a good swing for beginners as well since there is less to think about. However on Kiran's web site/Youtube she demonstrates improvement with all levels of golfers including some professionals.
Anyway just thought I'd throw it out there that I was using this swing and finding it great so far. I had been using the Heard Super Swing which was also very effective however I wanted something with even less moving parts and I was fighting the hooks with HSS due to the super-strong grip. The MGS works with a standard grip which makes it feel more natural to me.