I have only used them once and the materials that I bought (which I couldn't completely see before buying) were so lame, so subpar (I guess I'm used to the many wonderful FREE lessons that are published by sites like Busy Teacher) that I wrote a review in which I was very specific about what was wrong with the material. About two weeks later, I received a very insulting email from the author/s, basically telling me off, that I hadn't had to buy it, etc. When I complained to TPT they basically said, sorry, we don't interfere with what the authors write but you can respond. Well, when I tried, they had pulled down the materials. Fast forward about two months and this is what I have just received even though I had unsuscribed from TPT. "This is MINE and you should only review things you have bought (?)I like how you are too chicken to sign your name. Grow some balls!" yep, these are supposed to be college educated, professionals. All I can say is that it supports my general feeling that there is no quality control in TPT, especially for the higher grades. The stuff that I bought (for Around the world in 180 days) was so badly done, it probably was written by some hack.