Having flown (170B) with ADSB in for the past 5 years, and PowerFlarm for well over that in my Sailplane a couple of observations. 1. ADSB is great for seeing traffic a long way away and therefore can plan accordlingly. It is not very useful in a very busy controlled traffic pattern such as KPRC where I fly mostly. 2. I would not trade my PowerFlarm in the glider for anything. It has saved my bacon (especially at contests) more times than I can count. Busy thermals aside, I have had several alerts on incoming finishes far enough in advance to be able to calmly and clearly manuver away from conflict. I did install a transponder so I can be seen by GA with ADSB in. Is there a need for ADSB in or out for the glider? For me the lack of funds, power, and panel space made the choice clear. PowerFlarm first, Transponder second to be "seen" by GA and commercial traffic, ADSB out last and only if its cost comes down significantly. IMHO

Cliff Hilty CH ASW27 C170B