No one has invited more controversy than the Oracle with his repeated dismissals of gold as an investment. And as today's Wall Street Journal points out, "since early March 1982 Berkshire shares are up roughly 22700%, versus 372% for gold." Today's another case in point. Buffett's fund (BRK-B, on the NY exchange), is up far more than the S&P500 is down while PF is down considerably more than the S&P is down. Of course, there are other funds that can be counted on to hold tight in a volatile market--Yachtman (YAFFX) and Parnassus (PRBLX) are two. But most fund managers can't match let alone beat the market averages. Consequently, an equally strong case can be made for dirt-cheap index funds like Schwab's SWPPX and SCHB, which not only have outrageously low fees (.09 and .07%), but allow you to invest small amounts with no transaction fees, practically a surefire way not to lose money in any market if you cost-average.
The problem with gold is that supply soon catches up with demand and there's too much of the inessential metal on hand to command ever-rising prices. Still, it makes sense to have 5% gold and/or silver in your portfolio, and PF, with its large commitment to Treasuries, has proven it can level out the bumps better than funds like GLD and IAU.
Good thought about the allocation to precious metals. If PRPFX makes up 20% of your portfolio, then you have 5% in precious metals. I also maintain a 10% weighting in a low-cost gold miner stock fund for a total allocation to precious metals/stocks of 20%. The latter has tanked and I am dollar-cost averaging on the way down.