Not for my 11 day trip, they are exactly the same, with the slight exception that TGM, based on personal experience, suggests caution (but doesn't say "avoid") on one weekend day at a certain park due to influx of locals, where Touringplans does not include that caution, because their research finds it baseless. To me, this is a good sign, double confirmation, based on two different modes of gathering research (qualitative and quatitative, I guess).
My family thinks there are some really valuable aspects to TGM, some details on what's happening right now at the parks, and some really good suggestions for touring that you cannot find anyplace else, but I never understand the claim that his "best days" are super unique. If that's all a person needs, they can get a list at touringplans.com for free.
Then again, I am one of those people that thinks there are positives and negatives to almost every product one can purchase, TGM included. I really wish my Volvo, for example, had better front visibility and a better CD holder, but I'm not returning it to the dealer for a money back guarantee. That particular sentiment with regard to TGM makes me absolutely unique on the DIS and positively alien on TGM boards as far as I can tell.