I bought Geno's DVD early on, when did he start it, 2008 maybe? I thought it was the best thing since sliced bread, and said that here at the time (completely unsolicited). It felt like a night and difference, in like 5 minutes. I thought I might really become a player after getting my head and eyes in the correct spot. I also met him at DCC a couple years later and he gave me some in person tuneups.
The thing is, in all those years, I still shoot about the same. I didn't change the pecking order in the pool room.
One thing I will say about Geno, that maybe other people hate on, is his enthusiasm. Reading his posts and listening to him you "want" to get on the table and hit some balls and try it. I personally like that a lot. I don't think its a scam of his, I think he is genuinely super enthusiastic. I just watched Tommy Kennedy vs Archer match on Youtube, and Geno is like Kennedy. Just extremely enthusiastic about pool and life.
So people are starting to cut him up in this thread, but Geno will probably respond to them with enthusiasm, and never cut them up back.
I think its the same for any training method, really. Whether its a head/eye alignment system like Geno's, or stroke grooving, or elbow vs no elbow drop, etc etc etc. You might improve a hair, or think you will improve a lot after the initial experience, but a couple years later, you are in the same pecking order at the local pool room.
Put me down for the fundamental reason players reach a certain level "and stay there" is.... Genetics
Nature over nurture
I also find it hilarious that people say there is a shorter learning curve if you do xyz as compared to hitting tons of balls for hours per day "like the pros do". Every single pro that has ever existed, everyone in their local room knew they were going to be a player in a few months of picking up a cue. Pros don't become better because the put in more time, more practice, etc. The rate of their improvement is 10x the normal player. Then too, the pro will plateau after a few years, just like the intermediate player. The difference is their genetic propensity to control that stick is much higher. Not some aiming system. Or a stance. Or a bridge. Or a still elbow.
Carry on