Gentlemen,  your idea of transportability is a valid one, it's a heck of a lot easier to carry a gold coin than a Hereford or a cord of firewood.

However there still needs to be someone on the other end willing to accept a gold coin for whatever useful thing you need and want to buy.

The fact that folks have accepted gold in the past does not necessarily mean they will be willing to always accept it in the future.  Gold has zero intrinsic value, unless you are a jeweler, dentist or a manufacturer of electrical contacts, etc.  

There still must be that assumption of convertibility, just as there is with the US dollar, if you want to consider gold as a currency rather than just another commodity.

Specifically, if gold is currently at $1200 and heavy feeders at $1.50, would I trade an 800 lb steer calf for an ounce of gold? No, I would not. 

In the end, this discussion reminds me of building backyard nuclear bomb shelters in the late 50s and early 60s....futile.  No one comes out a winner in a nuclear war. Much the same in a financial collapse. Better we learn to work things out.