Philip, as one who was in the fray, a question for you. I looked several times at the plane finder replay of the afternoon and noticed that theft turns then entry and holding pattern around Rush and Green were chaotic. I saw planes going directly away from Fisk seemingly at the same altitude as entries and backtracking on the same path (!!) and also a surging of the holding pattern from a nice circular pattern into a wad over Rush. It looked like the wad would sort out then all the planes reorganize (self organize) and finally, nicely, then approach ripon/fisk. . . then all turn away and the chaos almost repeated the pattern exactly. Was visibility an issue? Was it hard to enter the holding at Rush? Why suddenly would all the holding planes tighten the circle and wad up before re-entering the Ripon/Fisk/path? Will ADSB help this in the future to allow controllers to advise?
Any insight from the cockpit? Your thoughts are appreciated, I would like to fly in next year, my first.
BTW - I replayed about 45 min real time and saw that planefinder only had maybe 50% of the planes showing as the controllers were talking and releasing many more planes than were seen.
All of the left turns off of the tracks most definitely added to the chaos IMO. For one thing, it provided a steady stream of traffic into Ripon from what, to me, was a kind of unexpected direction. I also think that there was a lack of guidance for the people getting the "turn left, go back and start again" directive. I never got far enough to see what people were doing immediately after turning out, but I did see them returning to Ripon, and most were rejoining the fray right over the town. The effect for a new pilot arriving was that there was an already established line with no end in sight.
Later - maybe late Sunday, I'm not sure - they did get better about this somewhat, directing pilots to "turn left, fly two miles, and then go back to Ripon." So maybe this is another opportunity for improvement, having a better-defined procedure for when you need to break off past Ripon, either on your own terms or when directed by ATC.
For me personally, while I spent a lot of time Sunday flying a lot closer to other aircraft than I have in my life, for the most part I never felt unsafe. Everyone was going in more or less the same direction and being relatively predictable. The exception to this, and the time when I always felt most vulnerable, was when I'd attempt to establish myself onto the tracks and then decide I needed to bail out. This feeds into your question about backtracking traffic, and also my point above about some better guidance for the bail-out pilots.
Now, as far as the holds go...I never held at Rush, so I can't speak to that. Green ranged from OK to really interesting. When I first entered the Green hold Sunday afternoon, I was actually happy. I had a Cherokee in front of me, and all I had to do was follow him with good spacing. Once they opened up arrivals again I'd just follow him up the tracks when we got there!
Problem was, that organization fell apart over the course of about half an hour. We had some aircraft closely following the lake shore, others flying a circuit a mile or two outside the lake, a few randos flying right over the middle of the lake, and people randomly moving between these circuits. This was actually the point where I bailed on my first attempt, because I realized that there was no way this "hold" was going to get emptied in an organized fashion.
So here, too, there's maybe opportunity for clarification. The NOTAM simply says to make left turns around the lake, but what's more important - staying near the lake, or keeping a single-file aircraft line? If we're keeping single-file, what happens when there are so many aircraft that we're flying miles from the lake? What's the trigger point for "saturation?"
And then there's the real question, the one that must follow any suggestion for improving the procedure - how do we document and explain these improvements in a clear and unambiguous manner that can be understood by anyone?
Anyway, I'm getting long-winded here, so let me try and address what I think is the meat of your post: I did not feel that visibility of other aircraft was a problem. With my eyes outside, and my right-seater (also a pilot) doing the same, I don't think we ever had anyone sneak up on us. It was not easy keeping track of everyone, but with some intelligent triage (ie identifying aircraft quickly as unlikely to be conflict problems), we did pretty well, I think.
I don't know if ADS-B will help the controllers. I know it didn't help me, and that the traffic warnings from the 650 in my plane were extremely obnoxious. Next trip up, I may take the time to see if there's a way to generally suppress them, because hearing "TRAFFIC ONE O CLOCK ZERO MILES" every minute or so was definitely a distraction I didn't need.
Finally, since you mention wanting to fly in for the first time, I would say to remember that what happened this year was an aberration. For the most part, you can engineer your arrival to avoid the busy times, and I'd recommend that for any first-timer. The Saturday and especially Sunday evening before the show are typically the busiest, and I would avoid them, even having done this a couple times now. Hitting Ripon early in the morning is usually a recipe for a nice quiet arrival.
Of course, as we've learned from this year, all those guidelines I mentioned can go out the window if weather or other factors come into play, so be cognizant of those when planning your arrival.
Finally, preparation is key. Be able to explain how the arrival works to a stranger on the street. Be able to reliably fly your airplane at a chosen altitude and airspeed. Be able to put it on a spot on the runway, maybe a weird spot 2000' past the threshold.
I believe the arrival procedure is safe and uncomplicated, but that's no reason to not take it seriously. Unexpected things can and do happen, and as we saw this year, sometimes those things can make the situation really interesting and challenging.