Zaon appears to be a mode "C" receiver. It requires the conflicting traffic to be transponder equipped.
Correct. It is only useful for avoiding powered aircraft (or I guess a few gliders with transponders). I suspect there are few powered aircraft that would fly in IMC without a transponder.
Two aircraft approaching each other head on with their widgets singing and dancing - how does the conflict get resolved? In other words do they climb and descend or do both aircraft turn right and will the widget indicate what to do?
With a system such as PCAS as NoD says it would be folish to rely on a heading change to avoid traffic unless you could see the trafic or it was at a reasonable range and its range didnt start to converge again after the heading change. In fact with the basic version it only gives you a range, not a bearing. Adjusting to ensure vertical seperation is more reliable. At GA speeds there is a awful lot of time between systems like PCAS spotting the traffic and your adjusting your height / range to avoid whilst monitoring to see if the other pilot is taking the same action. I suppose you could get into a feed back loop where the other pilot reciprocated everything you did but I have yet to see this happen.
A Glider is unlikly to throw away 400 ft of hard won energy unless it is very sure there is a risk.
Ah yes, but guess how much energy you are going to throw away when you hit me.
Forgive me but I sense a reluctance on the part of the glider community to do anything proactive. Fair enough if you feel the risk just doesnt warrant it - I cant defeat that argument other than by repeating that personally I feel a lot more comfortable in cloud knowing that I have something on which to "rely" other than keeping my fingers crossed.
From this thread it would appear that less than 5% of the gliding community have taken up FLARM. How could I in good faith invest in that sytem when almost not a single powered aircraft is going to have the system and only 5% of gliders have bothered to fit it? In the alternative I'd bet that 95% of powered aircraft in IMC have a transponder.