I used TOG for 3 years. Loved it at times, and hated it at times...lol
Although we had a roller coaster ride relationship, it's a wonderful solid program. The problem for us was, I am a tweaker(I said it:)). I found my self switching out some of the books to many times, for VP, SL Greenleaf press etc. I disliked the prep time, and trust me by the third year my prep time was down to about 35 minutes a week. That included reading the teachers notes, making sure the maps, questions were printed out, books were assigned and crafts were ready.
So on a whim, I ordered Biblioplan (BP). It's simple, meaning virtually NO prep. The authors of BP admittedly picks it books from popular lists so that was done for me. Such as, books from, SL, Veritas, Greenleaf and more. It also schedules MANY of the Dave and Neta Jackson Trailblazer, a bunch of missionary books, SOTW and MOH.
I get my packet from BP. I go to Staples, copy 3 sets of maps, 3 sets of questions, copy the timeline pieces onto white sticky paper. I put my books in-order and I am done. My weekly prep consist of reading a couple of Parent Companion pages (10 minutes). Done. We do it 3x a week as scheduled it takes about 30 minutes to do. I LOVE it. I thought it was too simple, and I held off doing it for years. We are doing Year 4 this year. I have time to add if I want, I don't feel guilty for skipping stuff because it is a spine for me.
I was a huge TOG supporter, I have some of my childrens work in it (The Geography overlays) it's a great curriculum but, if you are a tweaker, it's REALLY hard not to add to an already over-the-top meaty curricumum.