Contests or events.........advantage 2.4 and pretty soon you're not going to have a choice, major man power is saved at events like IRCHA (900+ pilots) by not having to man a frequency control trailer.

Large clubs (both mine have nearly 200 members each)............advantage 2.4

72 mhz is perfectly serviceable........BUT it won't help you when some kid rolls up with a Walmart special, with no concept of frequency control, and before asking fires up his 50 dollar toy and knocks a 1000 plus dollar gasser or heli out of the air. Been there, done that, seen it happen.