Hi SL, only just seen this. I drove myself demented reading reviews of different places and eventually plumped for HCC. The course material seems very comprehensive, although some people have said that there are lots of typo's etc, but I have not found any yet. I am doing the Principles of Plant Growth,Propagation and Development course, because my aim is to learn to grow better plants, it seems that I will know an awful lot more after this course!
I will probably take the exam, but it's more for personal development. If you have an academic background it should be no problem for you! Let us know how you get on?