It's not simplistic at all.

I'm currently a junior in college, and I read this last year by suggestion of another student who said it was an excellent precursor to our college's Computer Organization course (haven't taken it yet, so I don't know). It was also one of the books given to one of the CS department's Outstanding Seniors last year.

The beginning is a little slow if you know some physics, but it picks up and gets really interesting.