Gas and lead are much more valuable in that scenario. Gold just makes you a target, especially bullion and coins. Gold jewelry (chains, bracelets, etc) aren't bad for "trading" but if you show up somewhere with gold bullion or coins then quite a few people with a bunch of cheap lead will be following you home. Regardless of how well you are prepared, that is not a good situation to be in.
You can be friggen Rambo for all its worth, one guy who is a decent shot with a shitty rifle from a rooftop is all it takes.
Besides, during Katrina gas was literally more valuable than gold. You couldn't sell a gram of that gold but you could get ANYTHING for fuel. I actually got a gold ring that I sold just last year for $240 on CL for 2 gallons of gas, I didn't want to give up those 2 gallons but everything has a price. I had a guy who offered to let me "borrow" his wife for gas (no way in hell I was making that trade). A whole lotta people think that 5 gallon gas can is going to keep that shiny new generator running for as long as they need it to or they can get out of town afterward on that single tank of gas. They are wrong and when it quits running they get real desperate real quick.
If you are "investing" for SHTF then fuel is king, period. You hoard all the gold you want to but I guarantee I end up with more gold in the end with my gas that is currently worth 1/1000th of what your gold is.