"He pays 20% on his sale of stocks in his MSFT, but only 10% on all his investments in companies that has assets under $50 MM (super capital gains)"
What rule is that? The super low rate is 18% but only for shares held more than 5 years. There is a rate of 10% (and even 5% for more than 5 years) but only for those in the 15% tax bracket.