I posted this in the other thread because somebody asked, but I changed from the 80D to the Canon R7 this year and changed from the EF 75-300 Mk I to the Mk II. I had some focus issues sometimes with the old setup. The R7 is better in that regard as is this lens. Still can't quite pull the trigger on an L series lens.
I don't find I use more than about 200mm of the zoom most of the time as you aren't that far away from the track. My buddy, who's the real photographer of our group, carried his 600mm zoom around all weekend but barely used it. He also used a monopod to pan with in low light for the first time and liked it. I don't have one.
I, too, experimented quite a bit because you can. Found that full manual was the best option to get any results just before nightfall. You'd think with all the settings on these new things, you wouldn't need manual.
Last time we found a nice spot around the Dunlop curve area where you could shoot above the fence but we never got there this year. Most of mine were taken from behind fences other than practice day in the grandstands.
I always think I'm done shooting for the day with so many already taken, but then you always find a new vantage point that might make for something. Plus I find it keeps me occupied.
I'm somewhat spoiled by Daytona as there are many more spots to shoot from there. Road America is my all time favorite place to shoot but they keep adding more fences
