I did the course and sat the exam in 2015, on its first presentation, and got a distinction, which surprised me, as the exam was very time-pressured, and some of the TMAs were challenging, to say the least. However, I think it is a brilliant course and took me to a new level of dealing with stuff you find nearly overwhelming, but, trusting your instincts and, having found a way through the fog, you also find you somehow emerge, miraculously, at the other side with a new awareness. It was all very interesting, and perhaps an introduction to working at a more advanced level. There were lots of errors in the original textbooks, but I think the OU will have rectified them. I completely recommend it if you are serious about advancing your ambitions in maths and, although I have to say it nearly killed me, as I have a massively full-on job, and was also caring for my elderly dad, i wouldn't have missed it. The stuff on Rings and Fields is amazing, as the topology, and cryptography. A lot of the material is really current and cutting-edge. God bless the OU for making the effort to create something at this level which you can do at home.