If you arent having interference issues you have to legitimate reason to change. The software is as good or better on the 7C and unless you are looking to shed the frequency pin there is no good reason to change.
If we all waited until we got a radio hit, to "legitimate" a reason to change, then we might all of already lost a model due to someone elses ignorance. There is absolutely nothing wrong with Spektrum, it's a great system, I've had no glitches whatsoever. This is a sore subject with all you Die Hard Futaba guys - It's like you want to beleive that your Futaba is better, so you have to put Spektrum in this category of 'Having to legitimate the change to it'
I can think of quite a few good reasons to change, even if you don't want to shed your frequency pin.
How about Model Match? How about dual receivers? How about higher frame rate and resolution? Here's the big one for you......
Joe Noobie pulls into the club you've been flying at for years, and he's brand new to everything, but he's got this great TX, and you and a couple other guys are the only ones flying that day. No One notices Joe Noobie over there getting his stuff set up and he turns his TX on before you know he's there. Ut Ohhhh...Joe Noobie happens to be on the same freq. and he knows not a damned thing about a frequency board. Your $2500.00 Heli takes a nose dive directly at you and your friends, almost decapitating you. Damn....Just think - If you had a spektrum, or if even Joe Noob had one, that would of never happened.
The future is spread spectrum. Whether Spektrum came out with it, or Futaba, or JR, or Airtronics - No matter who manufactures the equipment - the fact is - Spread Spectrum is better because the risk factor is greatly reduced.
That's my opinion, and you're entitled to yours, but man you gotta admit - there's plenty more reasons to "legitmate the change" than shedding a frequency pin.