liberty dollar

i would like to get those that are knowledgeable about currency systems opinions on the liberty dollar. i know the obvious things like fiat systems are prone to inflation and that inflation is basically additional money we deliver to the hands of government who just print more money. but i have a friend (who is a libertarian as well) that believes this operation is a scam, from what i can gather this is in part because they are taking your US dollars when exchanging them for their liberty dollars. obviously that rate is based on silver that fluctuates in value as well. any thoughts on this issue would be appreciated?