As long as you don't use baro altitude hold or GPS, you shouldn't be able to tell the difference in flight. I prefer the Revo, but I use the extra features, and it is about 5x more expensive. CC3D's are about $8 shipped on eBay.
There aren't a lot of heli guys here, and the devs are the same. Before I did it on a 700, I would install it on a mothballed old faithful 450, etc. and get it all working there first.