Does it work better within Radar/VHF range? IE does it default to traditional vhf tx/rx when able?
No, it only uses the dorsal antenna which is Ku-band:
http://www.panasonic.aero/InFlightCo...echnology.aspx
Panasonic exConnect network:
http://www.runwaygirlnetwork.com/wp-...nasonic-Ku.jpg
uses Intelsat Global Connex satellites
http://www.intelsat.com/infrastructu...coverage-maps/
For reference, Emirates use onAir connectivity which rides on Inmarsat satellites.
http://www.onair.aero/en/commercial-...s-how-it-works