Eric Greenwell wrote:

I wonder about this. Does anyone have an idea what percentage of the VFR
airplanes carry a transponder detector, including the low cost units?
I'd guess a majority of them do, but I haven't seen any numbers.

I would think it is actually a tiny fraction. Of all the planes I've
seen or been in over the past year, I can recall only seeing one of
these devices. On the other hand I've been in several with TIS and
one with ADS-B, but even that is a small percentage of the total.