FullWings: entirely agree. But ADS-B IS the standard, isn't it? the FAA mandate it and it's being pushed by EASA. FLARM, OpenFLARM, P3i etc. have just sprung up of their own accord as a "distraction" from the main problem: ADS-B has been too expensive in the past to install. Now, it's getting slightly cheaper to have certified GPS etc. but the cheapest option still seems to be uncertified GPS with PAW, giving you both ADS-B in and out. The equivalent panel transponder from Garmin that does that is about £5k.