I've been thinking a bit more about the situation created by these "compatible" receivers.
My conclusion is that they are a good thing for Spektrum and Horizon.
Why?
Well you don't have to look far to see that there are now some much better value alternatives to Spektrum on the market.
You can already get some pretty good low-cost RC products from FrSky, FlyDream, Corona, Assan, FlySky and a raft of other Chinese manufacturers. Spektrum has (whether they care to admit it or not) been hit by these "cheaper" products.
As a result of this (plus things like the AR500 issues), Spektrum may have already found their sales starting to drop-off.
By introducing a $15 receiver to the market, the Chinese manufacturers have actually done something that may revitalize Spektrum's fortunes.
Someone looking at the market yesterday may have discounted buying a new Spektrum system because of the comparatively high price of the receivers, when compared to the other Chinese-brand (but incompatible) options.
Today however, they may be more inclined to buy a Spektrum transmitter and some of their up-market receivers because they feel confident that they can equip their fleet of parkfliers for a song.
Note also that Spektrum's new radio will be an up-market offering, with 8 channels and telemetry. This is really starting to overlap JR's market -- which is perhaps another reason why JR is pushing DSMJ in countries outside the USA.
I can see that split growing wider (outside the USA) as JR starts to lose sales of its 9503/DSX9 to a telemetry-enabled Spektrum DX8.
As a famous Chinese philosopher once said "may you live in interesting times"
RCModelReviews.com, just the facts.