Can I ask why you decided to teach your children so systematically from so young?
Sure! My husband and I both went to Stanford University, where we both felt just average. What we noticed, were that the kids there from academically advantaged homes (children of alumni, children of alumni from ivy league schools, children of Phds, kids who had gone to prep school etc) found Stanford much easier than we did. It wasn't necessarily that they were so much smarter (although a lot of them were), but many of them were just better prepared.
My own parents who had gone to state college, did everything they knew how to do to prepare me for college. But what they knew, and the parents of some of these other kids knew, was really different.
I believe in making learning fun. I believe in spending a lot of one-on-one time with my kids, and yes, I believe in helping them accomplish as much as they can from an early age. Here is how I start teaching reading at 18 months:
http://teachingmybabytoread.blog.com/where-to-start/