Well, I guess this is in my ballpark, so I'll give it a shot

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First off, I spent alot of time researching the golf swing and differant ways to go, and in all of my research, I feel Hardy is the best golf philosophy around. I am not alone. Hank Haney, specifically, has said that Hardy is the most knowledgeable teacher in golf. The guy is a genius, and I DO NOT believe his book exemplifies very well what he really knows. I personally reccommend the dvd, but I do believe in both he trys to simplify it so that he does not make it over-complicated. Wait for the new book, PT Master class [ out this march ] for him to hopefully explain to detail everything, not simplify it. If you got to watch [ as I did ] some of his talks at the PGA teachers summit, and at Las Vegas, I think that you would agree.
On Hogan, alot of things he described in his book he did not do. As all golfers, the "feels" that he had did not actually take place. There are also many things in his book that are flawed, for example, that he advocates starting the downswing with just the lower body. Hardy talks about in his book how this has started the "stuck" position in golf. I do love the book, it was the first golf book that I felt was a good one, but I feel Hardy's ideas are much better. Hogan was deffinally a 1 planer, and on Jacobs note, he started Hardy on this whole thing. One day, [ this comment started his journey into the 1 plane swing ] Jim asked John about Ben Hogan, and his reply was "he swung everything on 1 plane." He is personally my swing model along with Sam Snead. I have not read Jacobs book, but to say that it does not contradict Hogan shows that alot of things Hogan sais in his book is not what he actually did, he did not swing anything like Jacobs advocates.
You could also classify it as everyoens a 2 plane swinger, and everyone else is 1 plane. I think alot of people get confused about Hardy's teachings. Why wouldn't you use 1 plane ideas if you were near a 1 plane swing? The idea is to decide what it right for you, then start taking out whats wrong.
I'm not familiar with the 2 plane swing as much, but will say this. You have to use the Big Muscles to power the club, you just have to. But, in a 2 plane swing, the arms are the dominant power source. A feel is a feel. I swung 2 plane for awhile, but I THINK that Hardy advocates [ as I was taught] that you must drop the club on plane, nothing about not using the big muscles to square the club. If you are a good ballstriker, than you deffinally HAVE to drop the club down onto the right plane to the ball in a 2 plane swing. I actually had this same flaw, too much starting the club with my lower body to the point where I was coming in too steep. But, I could not sucessfully answer your question because of the fact that I have stayed away from 2 plane ideals and instruction as much as I could. If you want, I could ask [ or you could, whatever ] some 2 planers in the hardy forum what they think.
Anyway I just wrote a ton. I'll end on this, that Hardy has improved my ballstrikign A TON. I really believe my handicap will be 3 strokes lower at the start of this year because of the changes I've made. I think that his information on the 2 swings is the biggest help for ameterurs, and I also think [ this was not in his book ] that the Twist and Throw [ part of Tiger's big swing changes ] will revoulutionize the golf swing for professionals. But, I agreee with Cypressperch in that to every man his own, whatever works, do it. But I think that Hardy can work for everyone is they try it. Hopefully I did a decent job answering your question!