I have been flying the 12FGA for two years. It is an easy radio to use. It has a full 14 channels. The case is plastic not metal like the 12Z, but it is well done.
I have flown turbine, gassers and large edf models and never a glitch
If you want a metal case then go 12Z if you want to save a substantial amount of cash go 12FGA.

Have you been to the Futaba website to look at the features of each.

http://2.4gigahertz.com/systems/futk9300.html

http://2.4gigahertz.com/systems/futk9200.html