I am an obsessive planner and I subscribed to both TGM and TouringPlans and just got back from our first trip a couple of days ago. Here's what I think. If you are computer savvy, TGM is a better investment because he must have hundreds upon hundreds of pages of information on every aspect of Disney. That said, I had a very difficult time navigating it. I came into it thinking that I would just plug in the dates I would be there and he would spit out a touring plan for me. It doesn't work that way at all. It's more like he recommends certain things, but you have to plug it in to a touring plan for yourself.
Now if you fit into a specific category like "Parents with young kids" or "Active Seniors" or "Parents with tweens". I think it is easier to use Touring Plans. They don't have long essays on every single thing at Disney the way that TGM does, but it does have about 20 touring plans that would be good for a lot of different interests. So if you're not computer savvy, and willing to do a bit of outside research yourself, Touring Plans is a better deal.
I'll tell you what I did that made a huge difference to our trip. I got a PassPorter book just for the maps. The maps in PassPorter are the best I have come across anywhere. They are in color and marked for everything. They will give you a clear idea of how to navigate the parks better than anything else out there. Then I got the Unofficial Guide from the library and made notes on which rides would most appeal to our family and any extra tips that would be good to know. Then I designed a personal touring plan just for us.
This is the best information that TGM and UG gave me:1. that you can ignore the expiration time on a Fast Pass and use it any time after it begins. And 2. that you should get an FP based on every one in your party's tickets, not just the ones who want to go on that specific ride and 3. Get there when the parks open, it will make a huge difference to your entire day. Figure out which attractions/eateries you want to hit, find out where they are on a map, make your own touring plan and get there early!! You will have an easy time at the parks, or at least a whole lot easier than the myriad uninformed tourists there.
We had 16 people in our party of various ages, so we made a Thrill Schedule and a Mild Schedule. Our FP volunteer gathered all our tickets as soon as we entered the parks, and then we separated. The thrill group of 7 would immediately get two sets of FPs and then get in the standby line for a roller coaster. By the time they were done with the first, it was FP time for the other two and they would immediately get on those as well. There were only about 2 or 3 restricted thrill rides in each park, so the mild group would do about 3 kiddie rides. We would meet up in the playground of each park and then spend the rest of the day together. The thrill group usually collected one more set of FP's for some show or ride that we could all go on in the evening as well.
If I had to do it again, I think I wouldn't have bothered with either subscription. I got all the information I really needed from the books and Disboards. I did use the template for an itinerary from TGM, but could have made that myself. I didn't bring anything from Touring Plans. The color coded crowd days didn't have much effect on us, because which park we hit on which day was based on the pre-arranged activities we had planned (e.g. the Grand Gatherings Safari Celebration Dinner was only offered on Sunday, so we had to go to AK that day, even if it was red). But the truth is that the vast majority of people DO NOT arrive in time for the rope drop, so if you do, you are already ahead of the game, no matter what the crowd meter reads.
HTH,
Jil
Tons of up to date info, best days for parks, timing for rides, menu's...everything!! He was a VIP guide for WDW so he knows it very well 
Have you been to WDW before or recently? If you have, maybe the UG will be just fine. I ended up buying both the UG and TGM. I took my UG with me and some pages I had printed off of TGM. Since I had never been before, I really liked TGM suggestions. As a newbie, I liked TGM because he had pictures of the resorts, suggestions on where to sit in the shows & parades, & tips on how to score extra points on Buzz Lightyear. His program goes by individual days too. Where UG might tell you the crowded park based on a month, TGM does it by a particular day. He also puts the current schedule up since Disney will extend hours on certain parks depending on crowd level. He has an easy "green, yellow, red" crowd gauge.
