Hi,
I am personnaly running the CGY750 on my E6, and although i have always been a JR/Spektrum guy it has been a learning curve for me to learn the Futaba Ways of programming but the system is very good, both the 8FG Super which i went for and also the CGY750 work great together.
Any FBL system will be fine with a little 'tweaking' to suit the machine and also the pilots personal preference, but i would however recommend choosing a FBL controller that you have had expereince with or one that you can get help with if you need it.
I have my E7 in E6 configuration at the moment and it's great fun with the 4300mah 10S pack i run.