My point is that four years is entirely to short of a period of time to be President. By the time the individual is elected he may have a year or two to get something done then he turns around and starts campaigning again. If he wins a second term he is likely to have an opposing congress and then gridlock ensues until the end of his term. New President, repeat cycle. With a six year presidency the individual could get right to work.
6 years is too long without a choice. Only France has had a comparable term length in the modern era, and they changed it.