On several occasions, Kanigel tries hard to describe what Ramanujan is not. Kanigel has obviously spent considerable time in India, where the hype surrounding Ramanujan is tremendous, compared to America. People in India strongly believe Ramanujan couldn't put a foot wrong. Well Ramanujan was wrong, albeit only very few times. But he has made an error or two. So Kanigel tries to put in perspective the few instances in which Ramanujan was wrong. The case where Ramanujan claims to have found, a function, for the number of prime numbers less than x (for example if you supplied a value for 'x', say 32671, then the function would tell you how many prime numbers fall between 0 and 32671), is quoted in great detail. The only problem I had with this is that I was always cut off from Ramanujan's hype. So would most American readers. In an attempt to compensate, balance, and possibly moderate an invisible hype surrounding Ramanujan, Kanigel's presentation of 'both sides' comes out as rather negative. In fact upon reading the book, you don't immediately get why Ramanujan was called a genius. Kanigel uses a lot of subtlety in saying that. You have to pause and think before going - wow! I felt the positives could have been highlighted in more detail - even if it was done so with the aid of metaphors - so that a uninitiated reader can understand the reason behind Ramanujan's genius.
Another negative aspect that I found about Kanigel's presentation of Ramanujan's story was his filling up of gaps in Ramanujan's life. He knew about India's struggle for independence, and the first world war. Both happened when Ramanujan was reasonably close to ground zero. And Kanigel weaves a narration that implies that Ramanujan's life could not have been left untouched by such factors. I have my own doubts on this. However, on parts of the book that indulges in social commentary, Kanigel does not say his opinions in his own words. He carefully cherry picks and quotes other authors of Politicial, social books of that time to make his point. I thought this was an interesting way to narrate your point without being apolitical.