I'm all for 2.4ghz, and own a DX9 and DX18G2, but also I get not wanting to swap out a dozen 72mhz receivers for 2.4ghz, when my Futaba 9C has always worked flawlessly... I bought it brand new and know very well the history of my tranny, and I hope you do too. Most of these that were well cared for still work just fine.
I'm also not a fan of swapping a transmitter module back and forth to go from 72 to 2.4 and back.. just to fly my 72mhz planes. The pin systems on those modules can get fragile if handled too much.. which is why the one and only swap I made on my 9C was to the synth module.
... and I wouldn't be commenting if I didn't have first hand experience with this. Although 72mhz isn't common anymore, it's still used in many places, especially undeveloped areas, and it works just fine.