My advice is to talk to people and ask them what they want the radio to do that their radio DOESN'T do. Find out the limitations of the radios, because they all do things well and all have some kind of limitation.

My experience was upgrading from a Futaba 6ch to the Airtronics 8ch. I found that the Airtronics lacks the capability of independent setup of dual aileron throws, even though it has it for dual elevators. It lacks dual rates on the rudder; this can be programmed in using one of the C-mixes, however since all C-mixes are controlled from the same switch, you essentially are giving up your other mixes (for me, I wanted to use one mix to slave my rudder to my throttle; unfortunately this mix would only be active when the dual rudder was turned on, which obviously didn't work for me). These features (or lack thereof) affected me in a negative way, but many/most people may be able to work around them. I fly in competitive events and thus have my own individual requirements/desires for my own radio.

I have not met many people who are unhappy with the Futaba and Spektrum 7 channel radios. If I were to do it again I would have started with the Spektrum DX7. I am currently on the market for the JR 9ch.

As I said, each of the big radio companies have great products in the 7-8 channel range. Each one does something that the others don't do, and each one lacks features that the others may have.