At a crossroad, Stay with Airtronics or change to Futaba!
Wringitout;
If you have Airtronics equipment why switch? RD6000 is a superb 6 Ch Radio with all the features of the High end Futaba's. Programming is straight forward nothing hidden and it holds 8 Aircraft memory. Owning 13 Airtronics radios, I guess i am a little biased but not really. I've purchased Futaba(6XAS) for my Son-in-law and grandson, but only because majority of the members at his field had Futaba and it was easier to help him with a trainer cord while I visited.
Do you have a Need for all the Bell and whistles of the 9 Ch Futaba? Especially when the 6 Ch will work for you with all of it's options currently available.
If you want another Radio or Radios in the mix look at the Hitec Spectra it has a synthesized Reciever so you need not worry about who's on your freq. and it's a 7 Channel and in your price range. It as well as Airtronics will work with your current equipment as well as JR and Futaba.
Multiplex Cockpit is another very nice radio but the price is a tad spendy,
Personally I wouldn't change stay with what you know Airtronics!