Well Turbs, as a strictly VFR amature pilot, I would like all the help I can get.
I fly from/in the Sydney Basin, have dual channel transceiver, ADSB, OzRunways, eyesight and brain. The latter two, are dubious assets at best. The human eye is ill adapted to see other aircraft in flight and the brain, though astonishingly adaptable, makes very marginal three dimensional location "images"/spatial awareness, of aircraft, based solely on radio transmissions.
I don't know that the various EFB's operating systems have the potential to "talk" to each other but if they do, the low cost/weight, to enhance pilot spatial awareness of other aircraft in the vicinity can only be a good thing.
I do not see "the circuit" as the problem area - generally pilots are where they should be in the circuit (or close to it) and other pilots know where to look for/avoid/fit in with, them. I find it's in the training area, approach to circuit/ lanes of entry, waypoints, where there is no specific requirement for aircraft positioning, that the potential conflicts seem to arise. It is in these areas that it's easy to miss seeing/locating another aircraft, even when they make the appropriate calls. Having a blue bubble/icon with the position in space and direction/speed of travel of other aircraft in my locality, would be of tremendous assistance.
"..............once people start relying on it you need the same redundancy and build quality and training and currency as IFR..........."
No offence intended but this is a spurious argument and indicates a level of conservatism that can only hinder cost effective safety improvements
"Way back when" I was trained, (in less congested airspace) radio communication was much more formulaic and frequent. My spatial awareness sharper. Since then radio communication has been liberalised and frequency reduced. At the same time GPS/cost effective transponders have arrived and EFB have faux radar, vastly improving spatial awareness. Why not go the next logical step and have EFB's, of all types, "talk" to each other????