Futaba 7C FASST vs. Spektrum DX7: advantage holder named first:

-Spektrum DX7 has 20 model memory while Futaba 7C FASST only has 10
-Futaba 7C FASST has a proper "trainer" switch while DX7's is poorly placed and akward to use
-Futaba 7C has dial for variable flap adjustment versus DX7's 3-position switch (none/half/full)
-Spektrum DX7 has Model Match feature, 7C FASST requires you to verify your model selection prior to flight
-Spektrum DX7 comes with high capacity 1500Mah tx battery, 7C FASST comes with 600Mah tx battery
-Futaba 7C FASST is user switchable from Mode1 through Mode4, Spektrum DX7 cannot be changed without sending in for service

Each pilot will have to evaluate for himself which advantages matter most. I have a 7C 72Mhz radio system and fly Airtronics RDS8000 and SD-10g for 2.4Ghz. While I've never flown with a DX7 transmitter personally, I think it's a fine transmitter for pilots who don't need to instruct students. Just remember to set up a throttle kill mix before that first flight!