The central planners will always support gold in favor of silver, to draw people from silver to gold, because they have the gold stocks to control the price anytime, and they can drive the price of gold to whatever without hurting much 3rd parties (the industrial usages of silver). They don't want to hurt the industrials or those that buy those products. So that over-valued may be as true as a duck quaks, it's how it is, and saying that gold is overvalued won't change that.
My reason to chose silver above gold has nothing to do with temporary over or undervaluations, but because I find it a 'no' to try to evade the central planned theft along the fiat market, by entering another market (gold) they control aswell.