I made the change to 2.4 when I had a need for a better radio. My 72mhz was working fine, (though I was on one of the most crowded channels in the club), But I felt the need for more features, model memory, timer, extra channels etc. When I bought my 7C, it just made sense to me to go with the 2.4G version. Since I didn't have a lot of planes at the time, the cost of receivers wasn't a big outlay at the time. I still have one 72mhz radio, it's a Hitec AM 2Ch in a HobbyLab SR-71 that I intend to get flyable this year.

and thanks, gsoav8r, I just killed 15 minutes reading and laughing at that Wikipedia listing.