One of the drawbacks of JR's otherwise excellent DMSS system, as used in the XG8, is the cost of receivers. Here in New Zealand, the list price for the matching RG813B receiver is over $250 so when I spotted the Redcon DF9 listed on the HobbyKing website for just $32.48, I figured I'd have to review it.
Sadly, the Redcon receiver is simply no match for the genuine JR product.
Although the quality of construction is okay, and its low-voltage and relink performance is perfectly acceptable, the design of the antenna system leaves much to be desired and this was reflected in the reduced range and much greater levels of packet-loss even at close range.
Although the receiver would almost certainly work in many models, I would not commit anything other than a sport-type foam model to this unit.
Unfortunately, the extra bulk and those extremely long antennas mean that installing this receiver into a small to medium-sized sport model could be a problem though.
If you're flying gas, jets, 90mm+ EDFs, hotliners or helis -- give the Redcon a miss I think.