Finally pulled the trigger after uAvionix started shipping last month.  They ended up separating the ADSB transceiver ($1000) from the position source ($400) since many will already have a WAAS position source built into an EFIS or other NAV hardware. I don't so I bought the two piece package. Very compact and light. I put the magnetic mount GPS antenna on top of my battery box retainer strap in the top rear of the cabin, and ran coax out to a dipole midway out the right wing. The transceiver monitors my KT76A Mode C to snoop the squawk code and altitude for complimentary re-transmission with position added on UAT 978MHz, and delivers traffic and weather via WIFI to my Android Tablet running Avare EFB (free app).  A Galaxy Tab A, $150 new, provides a very nice and bright 8" display for moving map and navigation via Sectional, WAC, or a variety of other map options, up-loadable free from Avare with the latest FAA map data. Won't be using the 'out' capability until I get my Transponder tested and certified, but can start using the 'in' as soon as I start flying it next month.