ORIGINAL: Howard
I agree with airbusdrvr - everything I read indicates that the JR R921 is the same thing as the Spektrum AR 9000 except that it comes in a red case and says JR.
Hmmm. I just bought an X9303 system last night. The R921 receiver which came with it has a opaque charcoal colored plastic case. I also picked up a Spektrum AR9000 and AR6200 to qualify for the JR/Spektrum Giveaway rebate thing.
Plastic case on the Spektrum RXs is a transparent charcoal color. Aside from that, I see no difference between the two.