BRK-A was about $148K per share in Dec., 2007 and today it is $134K, down 9.5% in almost 5 years. Buffet made most of his money digging thru the pink sheets and buying little companies that investors overlooked. Some had more cash on the balance sheet than the company was valued as a stock. When you have a market cap of $222B it is hard to beat the market. He has run into the law of large numbers. In addition, BRK is really an insurance company and financials are out of favor. They need to start paying a dividend.
As far as PSX is concerned. It looks like a long term winner.