It is too much trouble to renounce your US citizenship to gain a little tax advantage. I think the US is advantageous to high net worth individuals. Warren Buffet showed his income tax return to extreme liberal media for one year and he paid just 15%. Most of us, who are US citizens probably, pay more than that. I am not really surprised as billionaires in the US have numerous tax loopholes. Now, even if you are just a millionaire or earn say $300,000 per annum, a good tax accountant is probably, worth its weigh in gold. Take note too that the US has the most number of billionaires in the entire planet by a very wide margin. If the US was taxing the high net worth, filthy rich billionaires, they would stay out of the US not, flock to the US.