We are still planning our first TGM trip, but I though I would speak up anyway.
We are arriving a few days before Presidents week and staying 9 nights, so we will be there for the worst of the week. In the past we have gone in the summer and during Christmas week. I noticed based on Trip reports here on the Dis that crowds seem to have increased, so I was stressed that President's Week 2008 may be busier than Christmas Week 2002 (which was wonderful, never waited in a line more than 20 minutes

, so I did something right).
I signed up for TGM to see if his site could help me. My family was worried that I would be making them stick to a strict schedule

.
What TGM has done for me is teach me how the crowds work, what to expect, and how to plan to stay ahead of the crowds and have a fun trip.
Could I have gleaned similar information on Disney boards, maybe. But when I started reading TGM and applying his philosophy to my plans, my stress about the trip evaporated

! Even when he just confirmed my decisions from previous trips, I now understand why the choices I made worked. This in turn makes our plan
more flexible.