Been using my JR 10X that my wife gave me as a birthday gift in 1996 and I'm using it to guide my almost 8 year old CARF ultra lightning rock solid ....
got a 9 Chanel jr Tx on 72mHz flying my all original 1999 hirobo EX WC Freya Heli..
got a 2002 Graupner MC24 guiding some of my vintage Hanno Prettner Supra star 60 and other ... Lately my dear wife bought me an 18MZ ...
So, from experience I can't see why changing radios as long as there's nothing wrong with them .... :-)