I find the whole processing speed issue crazy as well! My son is incredibly slow at writing and rote math, but can breeze through complex history lessons at remarkable speeds (he did a whole year's worth of lessons in two months). Last year, he devoured every medical book I could find, and he still remembers the details from those books. The whole thing baffles me.
We are homeschooling as well and it has greatly improved our lives. However, he is about to start going to a local school in the afternoons for Latin. I am hoping the processing speed issue won't be a problem there, since it is a very small setting.
Also, we've hired an educational consultant who tells us they can test for specific processing speed issues. I don't know the names of the tests, but she wants us to find out more about how our son sees words, etc. I'm not even sure it's worth the money, because it seems like these kids minds are really just out of sync during development. (We are confident he doesn't have any visual or other physical impairments.)
