The consensus seems to say 72 MHz over 2.4 GHz for a number of reasons - one being longer range at 72 MHz and the other being the risk of losing or damaging your copter if the 2.4 GHz system hits failsafe. That being said, Im flying a 2.4 GHz DX6i at present which is reported to have a range of about 700 meters - 2200 ft - so Im mindful of trying to fly within a 500 meter radius (perfectly fine for many locations). So far Ive had no issues and for learning and practicing its been perfect, but Im now about to fit a RangeLink UHF system to my old JR transmitter so I can head out to the countryside and explore further.