In One Person had many aspects are really liked. The way John Irving deals with all the different sexual tendencies is just amazing. He also treats AIDS in a wonderful way.
My problem with this book was however - as has been with most of his recent ones - that John Irving always writes about a persons whole life. The main characters are always of the age Mr. Irving was when he wrote the particular novel. So the older Mr. Irving gets the older his characters are. As he always tells about the complete lives this means that either the novels gets longer and longer - as happened with "Until I find You". Or the novels are of a normal length with some episodes in a persons life being told in lots of detail and others being told in fast motion. That's what Mr. Irving did here.
In Mr. Irving's novels I've always loved the childhood/youth parts most which unfortunately were the shorter how older he got. In "In One Person" however this part is the longest (I'd say that about half the book) and I really loved that. It's also perfectly clear why it has to be like that: during this time the most important developments in Billy Abbott's -the main character- life happen. Compared to this the rest of of Billy's life just seems unimportant, even when he makes one of his most important experiences: lots of people he knows dyind from AIDS. A better balance between these two halves would have been great.
My second problem with this book was the unrealisticly high number of transgender people at the boarding school. It is well known that at boarding schools there's a higher tendency towards lesbin or gay behaviour. But here half the students seem to be cross-dressers. I didn't quite get the point of that. It was even too much for Mr. Irving whose novel's are always crowded with extraordinary people.