I've gotten several tips on TGM that I haven't found anywhere else. I guess it is possible that I don't spend enough time reading all the other boards, and if I did spend more time, then I, too, would not find new stuff there. (I doubt it, though).
Then again, my time is valuable enough that that $20 is a bargain, particularly given the low signal-to-noise ratio on some of these boards.
If what you are looking for is a go-here/go-there plan, you can do that pretty effortlessly with TGM. There are lists of best parks on best days for various categories of guests (EMH-eligible vs. not) and times of year (accounting for EMH changes and holiday patterns). Mike's philosophy about why he picks which day when is a bit different from the Unofficial Guide's---and both tell you *why* they suggest the parks they suggest. Both probably lead to good plans. I think more like Mike does, so that philosophy fits me better.
Anyway, start with that list. Each day has 1-3 "best bets" for morning, and a separate list for evenings. Pull only from that list, choosing so that you see the parks in the order/frequency that you think best fits your family. Then, each park has between 2 and 4 pre-planned touring plans that you can just use. Unlike the UOG's plans, they focus primarily on the mornings through about mid-day, so if you really want an exact, all-day laundry list of what/when/where, they won't quite give you that. On the other hand, there is more explanatory text for why he plans things the way he does, making it easier to tweak the plans to suit your needs.
There's a lot more to TGM's planning philosophy, and it's really a philosophy, not a method. If you can get in tune with that philosophy, his site is a lot easier to follow. One big part of that philosophy is that "less is more" when it comes to being in the parks: he is a big advocate of afternoon breaks for everyone. He is a big advocate of not following a late night by an early morning. He is a big advocate of taking a day off from the parks entirely mid-stay to recharge your batteries. I don't necessarily follow all of this advice, but I do what I can.
If you haven't visited theme/amusement parks with this "less is more" attitude before, it feels like you are not "getting your money's worth"; I'll call that the competing philosophy. Once you convince yourself to try it, though, you'll never go back. I used to be a "get my money's worth" kind of guy. Then I bought season passes to my home amusement park, and the freedom of not needing to ride something with a long line convinced me that even when I visit other parks paying the full, one-day price it is better to follow the "less is more" philosophy. Most importantly, I believe I'm getting better value for my money because of it.
My recommendation: kick the tires, and try it out. He will refund your purchase price if you don't feel like there is value to you. I've gotten enough value out of it that I now recommend it, along with Unofficial Guide, to all of my family members and professional colleagues considering a WDW vacation. The total $40 investment is about the cost of adding hopping to *one* ticket, and provides much more value.