"and probably most people would agree with me about one of them—in each case"... So in what sense are these books overrated?https://twitter.com/prospect_uk/status/892419656455081984 …
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
It only makes sense if you think that when assessing whether something is overrated you don't factor in the people who think it's crap.
But he is factoring them in, isn't he? That's why he says most people agree with him about one of them.
Yes, he is - which is why he's wrong. If you factor in, the balance comes out that most people don't like either book. So why overrated?
I see what you mean. I suppose each book has an awful lot of fans who think it's just the best; whereas actually neither's all that good.
Yes, that's what he means. 
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.