I have read all of Harringtons books. And the first time i read them i thought they were the Bible. But since then i have looked at other ways to play. I have looked into the way Gus Hansen plays, and Of course Daniel Negranue.
I dont think you should restrict yourself to beign a harringbot. You will occasionaly go deep, but will struggle to make final tables (and or) with chips. I know that harrington has made 3 ME final tables, but that is with the very very slow strucature and massive fields of the wsop, where Playing only good hands early on keeps you in the tourney. For most players who cannot afford the mega buyins, then we have to make do with faster tourneys. I think this is where most people are going wrong with tourneys, they are playing way to tight during the middle stadges.
In Harrington vol 2, he talks about the colour zones etc. There is no way enough depth or material during this part of the book. And during his Vol 1, has anyone noticed that lots of hand examples are for online sngs......lol, i doubt that harrington has experiance with fast online sngs at a $20 buyin.
Anyway. im so glad that lots of people think that these books are the bible. Because these players are fairly easy to play against imo.
Having said all of that, they are great books as a base line. I would say that it helped me discover the importance of position, starting hands, short handed play and pot odds. But for more advanced stuff, you need to look elsewhere. For example, he does not go into changing you starting hands when the Antes kick in, doesnt tell you things like pot controll, detailed implied odds, blocker bets, bluffing outs and using scare cards against you opponents etc, he leaves out lots and lots that you have to find elsewhere.