Hi BoNeHeAd,
Out of interest, what make/type of ADSB Transponder are you getting fitted that transmits ADSB-Out?
Adding ADSB Out to your aircraft is great, I added it to mine over 5 years ago, and - as you say, virtually all receiver systems will see your ADSB, provided they are within range, but that's only half the picture. You will still need a receiver to display the other ADSB-Out units, and other traffic, so you know where they are.
If you also want to retain all the other great features of PilotAware, including Positional and Bearingless alerts for Mode-S, Bearingless alerts for Mode-C, Metars, and Flarm Rebroadcast from the PilotAware Ground Station Network and position reporting for all those PilotAware users out there who haven't added ADSB Out, - not to mention all the other great stuff that's in the pipeline, you will still need to maintain your PilotAware in fully functioning order - as without it's transmit function being active, you won't receive any of the uplink data (unless there is another aircraft nearby requesting the data - but that can't be guaranteed). My advice would be to retain your PilotAware in fully functional condition as your traffic receiver, in parallel with your new installation
In any event, you should never run PilotAware without the P3i transmit antenna (the longer one - or in your case the dipole) as this could easily damage or destroy the transmitter.
I hope this helps clarify the position.
Regards
Peter