We are in the same boat and I ask myself the same question all the time. My feeling it that it is not enough but it is the best that I can do. The one gripe I have with CTY (with the math) is that it is not enough practice. I just don't have the time to create worksheets for practice and w/regular busy work from school there is not a lot of time to even do those practice sheets. I figure it is better than nothing and whatever sticks sticks and what doesn't doesn't. Of course a true gifted school would be great but not an option. We did do one grade skip but still the schools are just soooooo slow.
You could supplement with something else. My DS9 has done a several Mindware.com books.
