For instance, at one point Dawkins says "Christianity was invented by Paul of Tarsus." (Or something like that; like I said, I'm working from memory here.) Of course Christianity was actually invented by Jesus Christ. The theory that Jesus was a fictional character invented by Paul, or that Jesus existed but that Paul invented his own doctrine, has been advanced by a few cranks, but I know of no real scholar of early Christian history who takes it seriously.
I, too, read the book about 5 years ago when I was still a Christian. I don't remember this bit, but I will comment that among liberal Christian and some emergent types this theme is reiterated. I read an author, Bruxy Cavey, whose book
The End of Religion was largely the point that Jesus never intended to start a religion. (To me, this just makes me question why Jesus couldn't have instructed his disciples better on this point.)
Regarding Dawkins' central argument against the existence of God, I find it so weak it's hard to know how to respond. He argues that a God powerful enough to create the universe would have to be more complex than the universe, and hence the probability of such a God existing is extremely low. That begs the question of how he's defining complexity and how he's defining probability. The textbook definition of probability only defines it in the context of repeatable experiments. Such a definition doesn't apply here, so a clear explanation of what probability means in this context is called for.
I don't recall the probability argument. I do recall the complexity argument--partly because even atheist critics seem to misunderstand his point. (So, either I'm wrong in my interpretation or he really wasn't clear. I'm inclined to the latter.

)
The point here, I believe, is that it is
creation apologists that insist that the complexity of the universe demands intelligence without explaining the complexity of the god that created it. This then leads to an infinite regression--something that cosmological arguers claim can't happen.
Obviously, Dawkins doesn't believe that complexity is required. That is rather the point of his book
Climbing Mount Improbable.
Now what he did miss here is that some apologists, as early as Aquinas IIRC, posited God as the ultimate simplicity--sounding an awful lot like Tillich's ground of being. However, most Christians in my experience have never even heard of such concepts.
I found the later chapters equally unconvincing. For instance, during one chapter he tries to argue for a negative association between religion and morality by pointing to a study of crime rates in America's red states and blue states, but states are divided into "red" and "blue" by how the majority voted in the presidential election, not by religiosity. State-by-state comparisons shouldn't be used at all to argue about the relationship between religiosity and crime when there's a wealth of data available on individuals.
This blog post primarily addresses Dawkins' claims about religion and education, but the first two studies listed also show a negative assoication between religiosity and crime. I'd be the first to admit that studies alone do not prove the point, but if Dawkins wanted to honestly deal with the topic, he'd surely inform his readers that there are studies showing a negative association between religiosity and crime.
Again, I could be misremembering, but the point here isn't that there is causation but rather that we can say that religion isn't necessary for morality. Obviously, as C.S. Lewis might say ala
Mere Christianity, those states and countries that are highly religious might be much worse off without religion.
It is also interesting to me to note that Phillip Yancey in
What's so Amazing About Grace bemoans these same sorts of statistics. (It should be noted that his book was written in the 80s).
Dawkins is surely smart enough to see the flaws in these parts of the book and many others. That raises the question of why he didn't correct them. Even if they somehow slipped past his attention, the editor should have caught them. Is he merely hoping that the readers won't be alert to these things?
So to sum up, I found it an unconvincing book with many obvious flaws.
Even if I am correct in my recollections, I would agree that the book could be improved.
One little irritating thing that I recall is that when extolling the beauty of the KJV, he attributed the phrase
Quo Vadis to it. The KJV isn't in Latin and according to Wiki it is part of the apocryphal Acts of Peter.