I have been considering freelancing route for a while. And the reasons you gave above are same for me.
In addition, I work in a big corp where I spend a lot of time red tapes formalities but contractors in my team only have to worry about their code and they get paid almost double some employees.
My question is how did you get started? I know you said subcontracting, is it through a consulting firm or do you do it through your own firm?