We used the UG and were able to get some specific date info from the TGM website with the codes provided in the current UG. It was a real help.
We travelled during the spring break and were concerned about the crowds- but all was well and we didn't wait any longer than 10-15 mins max the whole trip. I was amazed, this was our 3rd family trip and it went the smoothest.
That all being said, I think you are going to find it difficult to use a trip guide with the size of your group. In order for the guides to work, you have to have everybody in your group committed to using them. We were familiar with Disney already and didn't have the full blast of pixie dust in our eyes when we used a guide this year. I think for my first trip with the kids, it would take a lot to convince them to "pass on by" some of the rides. Even this time, I had to keep reminding my DH to "keep the faith" and stick to the plan. They were very annoyed with me at first, but after a few hours, they were starting to become believers.
I think that if you could at least read about what days/times to avoid the heavy crowds. Try to avoid the parks with the EMH, go back to your room or go for something to eat for the afternoons and get a fastpass if the line is more than 30mins. Hit the popular rides early and late in the day, catch the fireworks once and then next time, hit the rides during the show.
If you are armed with just these tidbits, you will at least have some basis for decisions that need to be made every 10 mins or so. I found that to be the best part of the guides, after a while my family would just look over at me and say "What does Mike say to do next?" It made things easy and I didn't have to spend my day thinking and wondering where to go. And if things didn't work out great, I could blame Mike!