Thanks. I read those posts and still could not figure it out, maybe I just missed it... I cannot understand why it is worth it - what it provides above other guidebooks....
I think there's a level of detail that you don't see elsewhere.
To take one example, when we went in May there was a new ride that opened, and while other guidebooks said , "do that ride first cause it's going to be busy", TGM said something like, "stand here in the crowd, then get to the left of the crowd, then walk to the ride this specific way, then send a runner to get a fastpass, then the rest of you get in line, then pretend to drop something so your runner can catch up, then try to get such and such a seat, then notice X detail midway through the ride, then exit through this specific door so you can beat the crowds to the next ride." It's funny, because after all this specific detail with a lot of italics, bolds and exclamation points, it always says something like, "but don't worry if you can't do this. You'll have fun no matter what." !
I just looked at my printouts for the parades and I think I had 16 pages just on which evening parade, when and where to stand and how to beat the crowds out of the park. For ONE park.
I do think this is unique. Whether it is valuable depends on how much YOU would value it. I found it made me worry about things I never worried about before. Other people love it (they are obviously less neurotic than I am!).
As far as best days, I found they overlapped considerably with the Unofficial Guide recommendations. I tended to do the park they both recommended.
Hope this helps.