I would prefer bitcoins because I know that the price of the gold is going down and I don't think that it's a good idea to buy gold because you will have first to use real money but with bitcoins you can earn money without spend lots of money.
It just depends on how you look at it. If you purely focus on this year so far, then you can say that for gold standards it has been doing pretty well.
But if you look at how the last 5 years have been, then you can indeed see that the price has been going down. But if you look at it from an investor's point of view, then it offers opportunities.
If you buy Bitcoin then you have to use money as well at the beginning. I just don't see how you compare an easy divisible currency as Bitcoin with something physical that doesn't lend itself for online micro payments.