Advantages????
Well you could gin up several identity and financial fraud schemes while committing felony tax evasion. You could annoy every other person in the US with frivolous law suits including every politician, judge, and law enforcement official (local, state, and federal) to the point that everyone who maintains citizenship in the USA would be willing to pay for your room/board and health care during a long stretch at Club Fed.
So if you really would like to be a sovereign citizen and you have aspirations of spending lots of time doing pushups and situps with your bunkmate in your 6x8, Via con Dios!
Be safe.