To each his own, to be sure. As a representative work in its genre, it may have merit. As to its literary merit, one of FR's favorite pundits, Mark Steyn, is singularly underwhelmed.
First, it's intended to be simply an entertaining mystery, not a work of substantive literary merit. Like just about every thriller and mystery writer today, no one will remember him or his books 50 years from now, unless they google him! Second though, I enjoy Steyn, a good political pundit. But make no mistake, his conservative religious persona creaps into his "review" of this book. He is clearly not an unbiased reviewer.