My Take
This site is free and offers a lot of resources for teachers. I really like the challenge problems because they really do help the students make those real world connections and help them to understand the purpose of what they are learning. My only issue was that it took forever to download the materials but it could have been my computer or internet connection. It was definitely worth the wait!
How I Use It
More often than not we here students complain that what we do isn't relevant to the real world. Well this site helped me to show my students how the math we use is used on a daily basis in the real world. They have these great daily challenges that offer additional problems for the students who are ahead of the curve. They work for small and large groups as well as if you assigned them as homework. Next year I may assign the additional problems as extra credit from time to time.