Thks for sharing your views ColinsMum. smile
I am not certain which way to go. As we will be moving again and changing school, I thought I would take a break for summer. It was DS who asked if I have renewed his CTY course! :P

I was abt to find out more abt the AoPs textbooks. Wondering if they would be good for self reading. It is not easy to get Higher Level Math/ Science books which are written in a more interesting (ie. not boring) way. The AoP texts reviews looks good. Thks for the link. I will run thro' them.
The Geometry Text recommended by CTY is "Geometry" by Ray C. Jurgensen. I think I will look into getting a 2nd hand copy first b4 registering for the course. I am also thinking of using this http://www.khanacademy.org/ for the meanwhile.

I think DS is motivated by how structured the CTY Math courses are, but they are not cheap. At this point of time, I am also thinking if it makes sense to consider a more rounded course (ie. diploma courses), since the international schools in general do not recognise the credit of the individual courses.