At the end of the day, the only thing that counts is the long term returns, and they are extremely impressive:
Berkshire Hathaway always uses "marked to market" for listed securities despite their limitations, Maybulk and Noble might want to take note:
It is the hallmark of the great manager to admit mistakes, Buffett does not try to hide the mistake he made regarding Tesco, about which I wrote here and here.
The last three sentences are a proof of the amazing stock picking abilities of Buffett and Munger.
Reviews about the year report can be found at Fortune, Forbes and The New York Times.