That's definitely one of their drawbacks. People seem to dismiss that criticism and say it doesn't reflect the spot price because its the value of usable gold, but I dunno about that one, seems like a stretch. 

The thing I like about them is, so far anyways, its probably hard to counterfeit them. If you hand me a silver coin or a goldback, I'm much more confident in my ability to look at the goldback and know its real. That's probably due to my inexperience with silver coins for what its worth.