The pilots at the Coupe Aéronautique Gordon Bennett make incredible flights. This page lists the currenlty longest distance and longest duration flown during the Gordon Bennett.
Those durations and distances are only little short of current World Records for those categories of balloon (AA-5 for hydrogen filled 1000 m3 balloons, AA-6 for helium filled 1000 m3 balloons). It has to be valued that the World Records have been achieved with a very specific record in mind, often waiting for a long duration for the right weather to arrive, and often in a single pilot cockpit allowing more balast to carry.
The incredible flights during the Coupe Aéronautique Gordon Benneett are achieved under given weather conditions and with the requirement of having two people and significant safety equipment on board.