Hi Eric
Very good overview article. Thanks for that.
I think you are maybe a bit too optimistic about the PCAS systems.
Please don't get me wrong.
I would still recommend everybody to get one.
But everyone needs to understand the limitations.
I don't have any pertinent data, but this is what I sense:
PCAS is not "watertight".
I hear continuous stories about missed threats.
Last weekend my (transponder-on) threat did not show up on my friend's
PCAS.
You already indicate that it works "well", not perfect.
To stay with your phrasing and adjusting it a bit.
If you fly in Reno area and have 10 surpises a year, the PCAS will
probably indicate 8 out if those 10.
But not eliminate all 10 out of 10 surpises.
My understanding is also that if a Mode C transponder does not get
interrogated (e.g. out of radar range), no threat will show up on your
PCAS.
For these remaining cases and all the other stuff without transponder,
you still very much need to keep your eyes out there.

All these tools are great to significantly reduce risks, but they do
not eliminate all risk.
The worst scenario is to replace the reduced risk with complacency,
assuming that everything is safe now with your fully tooled up glider.
According to Murphy's law, the remaining risk will come and bite you.

Hans Van Weersch
With "always-on, radio-checked" radio, "always-on, tested"
transponder, "always-on" instruments, 25Ah of battery (going to 31.5
Ah) and getting an MRX-A soon.