So why am I talking about this again? Because I just flew down from Alaska to Texas with my GDL39 on the entire way - and I'll share my experience with you.
At the beginning of the trip, from Alaska through part of the Yukon, I had another friend in his 185 along with me. He had ADS-B out so I could see him on Foreflight. Since I don't have ADS-B out he couldn't see where I was.
Now normally when I fly with friends we use this thing call "visual separation" (a strange concept these days I know) and radio communications along with showing wing when we loose sight of each other. But we were in some very low ceiling and vis and I'll admit it was quicker and easier to glance at Foreflight and know where he was.
Speaking of weather, flying anywhere, but especially in the north, knowing what's happening with the weather is critically important. And here ADS-B is useless (at least tower based ADS-B). I got no weather displays until I got into Texas. And Foreflight doesn't allow you to select your weather source (Garmin Pilot does) so if you are using ADS-B in with Foreflight unless there are ADS-B towers in the vicinity you won't have any weather info.
How about traffic on this trip. Well my 185 currently doesn't have ADS-B out so I have to rely on either towers or other aircraft that are out equipped (of which of course there are plenty). Other than my friend in Alaska and the Yukon, I didn't see any traffic displayed until Texas. And then they were everywhere, like no-see-ums- except I was seeing them (on the screen anyway).
My destination was Lockhart and as I got into the greater Austin area there were planes all over the display going every which way and at all kinds of altitudes. And I had Foreflight set to not show distant traffic (I turned that on once just to see and holy cow it was like looking at a Find Waldo picture).
As I got within 20 miles of Lockhart I started letting down from 3,500 feet. And then there he (or she) was. The little ADS-B triangle aimed right at me and descending. I thought it might be going to Lockhart as well. It was a little faster than me so was gaining ground. So I descended further and it continued on an intercept course also descending. Meanwhile I had a 172 crossing in front of me a few miles ahead and a little higher that I was gaining on- so I felt I had to keep my eye on that target as well. Plus all the others around me at all the other airports that may or may not turn toward me.
By now my attention was focused nearly entirely on my iPad at this bogey coming in quickly from behind and descending on me (which sucks because I'm no longer looking out the window where the real danger is). I continue to descend to an altitude I doubt he'll descend to keeping about 500' between us (according to ADS-B) as his triangle is now right on top of mine. I figured out he was actually landing at San Marcos, a Class D airport not too far from Lockhart so it wasn't long and I was out from under him.
Had he seen me? I have no idea. Would we have collided had I not descended? Probably not. The traffic alert of Foreflight never triggered, and those triangles have to be big enough to see on the screen so they represent a lot of airspace, and how many mid-airs occur every year- not very many. What really sucked was how much time I spent staring at the screen. I didn't like that at all. Plus there was a bit of stress through that entire ordeal which I didn't like either.
But I have decided that because I'll start flying the 185 to the Florida Keys every winter and with the density of controlled airspace I'd have to navigate around to avoid having ADS-B, that I am going to outfit the 185 with ADS-B out. That will happen while the plane is in Texas this winter.
But I will have nothing to do with ADS-B in. In my opinion, at least for me, it's a really really bad idea. So I won't be looking for your target (or any target) on my screen. Instead my eyes will be looking out the window as they always have.
Already have the MaxPulse for the Landing/Taxi light which is always on. But I'm also adding strobes all around the 185 for those coming up my six. She is getting wing strobes, a tail strobe/ADS-B out, and a rotating beacon strobe. this should keep folks off my six where I can't see them.
Thanks for letting me rant.

