My first transmitter was a Futaba 4 channel (whatever came with my RTF trainer). For my second plane, I bought a Futaba 6TXA. Great radio. But since my 2nd plane didn't work out (Tiger 2 kit, messed up the wings, ordered new ones, then the fuselage got flooded from leak in bathroom over my shop. I ended up throwing it away!), I got a Ultra Stick 40. With the 6TXA, the only thing I cannot do is full span ailerons (make the flap servos slave to aileron servos). Crow requires me to throw 2 switches (airbrake and gear switches. Flap servos are Y-d together to channel 5, which is landing gear on my radio). I have not had any problems with putting in mixes, etc. But this has only been my first season with the 6TXA.

My next radio will probably be a 9C. Nothing against the 7C, just I need more channels

The 6TXA was a good purchase for me. I could not have slipped the 9C into my shop (and onto my visa bill) as easily as the 6TXA. I think you will really enjoy the 7C. Not on your first plane. Probably not on the second. But after that, it is really handy to be able to do what you want without being limited by your radio. You will not have to look for planes based on what your radio can and cannot do.

For those that were saying about dual servos, I have heard that for the bigger planes, you usually have 2 receivers anyway. So one receiver failing would not cause you to lose your plane.