Buyer beware on the Freeflight solution. I've installed the Freeflight FDL-978-TXL (this is not the model that has the wifi capability, I use Stratus for "IN"), thinking this would get rid of the "hockey puck" issue with receiving traffic by equipping the plane with ADS-B OUT. However this unit does not transmit to the ground the fact that the plane is capable of ADS-B IN.
In short, the OUT unit has to tell the ground that IN is installed in the plane; without this, the traffic picture is NOT sent to the plane. It turns out that Freeflight did not include this capability in this model. They have been working on a software fix for several months however the release date continues to slip.
Before you install this, I suggest you contact Freeflight and confirm when they will finally have this fixed.