I agree with others who said TGM's site is hard to navigate - it's badly laid out and not user friendly. I also agree that he has some outdated info on there and the touring plans need some updating but I can honestly say his Least Crowded Parks information was incredibly accurate and his touring plans (although not entirely updated as I mentioned) are excellent.
If we go back to WDW I will definitely be paying the subscription fee again just for the Least Crowded Parks information alone.
Time and time again, on our trip last October/November we were in the shortest bus line of all 4 parks - for example, we would see the hordes of people queueing for AK or MGM or Epcot while we were with a handful of people in the MK bus queue. It got to the point where we could tell which bus stop we needed in the mornings from just looking at the emptiest line. Honestly - amazing!
Regarding the touring plans, well it's best to take his plans as a starting point, like a template (a really really good one!) and then add in or remove any attractions that a) he didn't include yet or b) you do/don't want. If there's an attraction he hasn't included yet in a touring plan, chances are, he will still have info on it in the Attractions part of the website so just cause it's not actually in the touring plan doesn't mean he hasn't offered advice on it on his website.
Sorry this got long-winded and just to complicate things more, I also love The Unofficial Guide - it's a terrific guide book and, in my opinion, an invaluable asset to anyone planning a trip to WDW - but nothing can beat TGM's Least Crowded Parks info - truly amazing.