I have a few months ago been selected to host a FR24 box(F-KENL1). Since then I have been experimenting with other antennas and playing around with a flightaware dongle on a raspberry pi using Piaware.

I have made three coco antennas recently. all using TFC-T10 RG11 tri shield coax with 85% VF

an 8 element (7 plus top that is 1/4 / 1/4 stinger that shorted) (116.75mm)
12 element same thing
8 element with the other calculation in this thread that used a longer wavelength for 1/2 wave (maybe 124 or 126mm)

Using the FR24 antenna as a base plot, I got these

FR24 - 450 msg/sec, 240 miles -79 ac tracked
8 element 116.75mm -420 msg/sec, 240 miles, 91 ac tracked,
8 element with longer wavelength - 350 msg/sec, 170 miles, 81 ac tracked
12 element 116.75 - 370 msg/sec, 210 miles, 87 ac tracked (maybe not tracking good right overhead since higher gain)

NOTE - the FR24 is 5ft higher then the rest of the coco antennas since it has the best spot on the mast to mount it so it can see better over the pole barn in the next lot to the north. Every other direction has trees so north is the best direction I receive from

Dont have any better measurements, but thats the best I have without nice test equipment. Not using a preamp or any sort of tuning adjustment, just rg6 30ft length straight to the flightaware dongle.