The Common Denominator
I don't care what training method you use, what exercises you do, or what diet you're on, if you're not consistently working very hard on a long-term basis, it's not going to pay off.
The common denominator isn't the method, it's you. That might seem like a bitter pill to swallow, but there's a bright side: You have full control over your consistency and work ethic. It doesn't cost anything, and no one can take it away from you.
As you become more experienced, you'll need to do more and more work for less and less gain. A beginner can put 10 pounds on his squat every week, but eight years down the road, he'll be thrilled with 10 pounds a year.
All forms of biological adaptation follow this pattern. The closer you get to your genetic ceiling, the slower the adaptations come. I bring up this point to make you aware of the (admittedly depressing) fact that plateaus are inevitable at some point. It doesn't mean you're using the wrong methods, and it doesn't mean you're doing anything wrong.
Even the best methods require consistent hard work. Even if you manage to find that "perfect" program, diet, or exercise, it won't do a thing for you without hard, consistent work. And oddly enough, even "iffy" programs deliver in spades when you go after them hard enough.
Worry less about the program and more about your personal work ethic.