I haven't read The God Delusion yet. I've read The Greatest Show on earth, and I didn't like his style at all. In parts, it was very intriguing, and in others it was quite tedious. He seemed to pack the book full of stupid anecdotes that had little to do with the subject matter. His foot notes in that book were absolutely wretched! It's seemed like every other page had a footnote, and most of the time I finished them saying to myself "Why the fuck was that necessary?" Some of these footnotes were actually up to an entire half of a page!

such simple language that it's borderline insulting the readers' intelligence.

I wouldn't consider it "insulting to intelligence." Dawkins makes a strong attempt to make his work appeal to a wide audience. He wants his work to be accessible to those who are not necessarily academically inclined. I think we must withhold criticism of his simply language as it was, in fact his intention.