Holding spot gold versus gold miners is a matter of individual risk tolerances and investment goals. Gold miners will be much more volatile than spot gold, and can be considered as a 'leveraged' play on gold. The high leverage that gold miners can take on by quickly ramping up or down production allows for larger price movements than gold itself, but this also works against investors when the price of gold is falling.
Largely, we feel that if investors believe the price of gold will increase and that miners are trading at a good valuation, we would see gold miners as the better play. However, for a more conservative approach, we would prefer holding a physical gold ETF, such as GLD or PHYS. GLD has a longer history and a larger AUM than PHYS, and so this would be our preference today.